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<article id="post-Low-Level-Design-1-Todo-List" class="article article-type-post" itemscope itemprop="blogPost">
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<a class="article-title" href="/2024/10/15/Low-Level-Design-1-Todo-List/">Low Level Design 1 - Todo List</a>
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<p>I recently came across the “machine coding” round, also called “low level design” round, of the tech interview process. In this round of the interview, you’re presented with a real-life problem statement, and are expected to create a functioning system in under 90 minutes. The intent is to see how you structure your code, follow best practices, apply design patterns, and so on. In the spirit of practising for this round, this blog post looks at how to create a simple todo list application in Python.</p>
<h1 id="Problem-Statement"><a href="#Problem-Statement" class="headerlink" title="Problem Statement"></a>Problem Statement</h1><p>Let’s start with the problem statement: create a todo list. The very first requirement that comes to mind when creating a todo list is the ability to add tasks to the list. For example, getting groceries. It’s also possible to add subtasks to the list. For example, getting apples and oranges are subtasks when getting groceries. The todo list may be shared with family and friends. They receive notifications when items are added or removed from the list, and have the ability to add or remove items. Only the one who created the list and the ones with whom the list has been shared may modify the list. The todo list may be displayed in the console or in the webpage. Finally, the todo list may be persisted in the database. </p>
<p>With these requirements in mind, we’ll begin by looking at the classes and methods that comprise our system, the design patterns we can apply, and finally go ahead and create the system. Please note that since the implementation is going to be in Python, it may seem like I’m trying to do Java in Python by creating too many classes. For example, Python has the concept of “factory function” rather than “factory method” since functions are first-class citizens of the language. You’ve been warned.</p>
<h1 id="Design-Patterns"><a href="#Design-Patterns" class="headerlink" title="Design Patterns"></a>Design Patterns</h1><p>Let’s begin with a quick refresher on design patterns. In a nutshell, design patterns allow us to write reusable, maintainable, and testable code by providing patterns for solving common software engineering problems. These patterns can be categorized into three types: behavioral, creational, and structural. Behavioral patterns describe how objects interact with each other. Creational patterns describe how objects can be created. Finally, structural patterns describe how objects can be composed to create larger systems. </p>
<p>In the context of the todo list, we’ll see the following patterns being used. We’ll take a quick look at these patterns and then map them onto the classes we’ll create.</p>
<h2 id="Composite-Pattern"><a href="#Composite-Pattern" class="headerlink" title="Composite Pattern"></a><a target="_blank" rel="noopener" href="https://www.gofpattern.com/structural/patterns/composite-pattern.php">Composite Pattern</a></h2><p>Composite pattern allows us to represent hierarchical, tree-like, data structures. The intention of this pattern is to ensure that composite objects (the non-leaf nodes), and individual objects (the leaf nodes) are treated the same. The UML diagram is given below.</p>
<img src="/2024/10/15/Low-Level-Design-1-Todo-List/composite_pattern.gif" class="">
<p>As we can see, the non-leaf <code>Composite</code> class is itself a <code>Component</code> and has a collection of <code>Component</code>s. These may be <code>Composite</code>s or <code>Leaf</code>s. In our todo list example, we can model the the tasks and subtasks using this pattern. We begin by creating a top-level abstract class <code>TodoItem</code> which corresponds to top-level <code>Component</code>. The subtask can be represented by a <code>SubTask</code> class and is the <code>Leaf</code>. Finally, we’ll create a <code>Task</code> class which is the <code>Composite</code>.</p>
<img src="/2024/10/15/Low-Level-Design-1-Todo-List/todo_composite.png" class="">
<h2 id="Adapter-Pattern"><a href="#Adapter-Pattern" class="headerlink" title="Adapter Pattern"></a><a target="_blank" rel="noopener" href="https://www.gofpattern.com/structural/patterns/adapter-pattern.php">Adapter Pattern</a></h2><p>The adapter pattern allows disparate components to work together seamlessly by reconciling differences between interfaces. It does so by providing a familiar interface that the client can talk to, and in turn using the interface of the underlying component. In other words, adapter pattern translates from one interface to another; the adapter calls specific methods on the adaptee when it is invoked. The UML diagram is given below. </p>
<img src="/2024/10/15/Low-Level-Design-1-Todo-List/adapter_pattern.gif" class="">
<p>In our todo list example, we can model connection to database using a <code>DatabaseAdapter</code>. This allows us to expose a familiar set of methods to perform operations like saving the todo list to the database while abstracting the nitty-gritties of the actual database. This class can then be subclassed to provide functionality for specific databases. For example, a <code>MySQLDatabaseAdapter</code> for using MySQL as the database. </p>
<p>The advantage of using this approach is that it allows seamless migration between databases; we may start small with <code>SQLiteDatabaseAdapter</code> and then switch to <code>MySQLDatabaseAdapter</code> by simply changing which class we use. Since the interface exposed is the same, there will be minimal refactoring in the client code to make this transition. </p>
<img src="/2024/10/15/Low-Level-Design-1-Todo-List/todolist_adapter.png" class="">
<h2 id="Strategy-Pattern"><a href="#Strategy-Pattern" class="headerlink" title="Strategy Pattern"></a><a target="_blank" rel="noopener" href="https://www.gofpattern.com/behavioral/patterns/strategy-pattern.php">Strategy Pattern</a></h2><p>The strategy pattern allows defining a family of algorithms, encapsulating each one, and making them interchangeable. This means we can define and pass algorithms around. There is a base class <code>Strategy</code> that defines the interface for the algorithm, and one or more concretions that provide the actual implementation. The UML diagram is given below. </p>
<img src="/2024/10/15/Low-Level-Design-1-Todo-List/strategy_pattern.jpeg" class="">
<p>In our todo list example, we can design the rendering of the list as a strategy. For example, we can have a markdown strategy, an HTML strategy, etc. These different strategies produce different representations of the todo list.</p>
<img src="/2024/10/15/Low-Level-Design-1-Todo-List/todolist_strategy.png" class="">
<h2 id="Proxy-Pattern"><a href="#Proxy-Pattern" class="headerlink" title="Proxy Pattern"></a><a target="_blank" rel="noopener" href="https://www.gofpattern.com/structural/patterns/proxy-pattern.php">Proxy Pattern</a></h2><p>The proxy pattern encapsulates an object and allows itself to be used in place of the original object. Since the proxy is used in place of the original object, it enables use cases such as controlling access. There can be methods on the proxy which require authentication before the operation is performed on the original object. </p>
<img src="/2024/10/15/Low-Level-Design-1-Todo-List/proxy_pattern.gif" class="">
<p>In our todolist example, we can create a proxy which ensures that only the owner of the list and those with whom it is shared can make changes to it. To do this, we’ll create an interface called <code>TodoListProtocol</code> which defines methods which the todo list must implement. This will be used by the <code>TodoList</code> class, which represents the actual todo list, and by the <code>TodoListProxy</code> which provides access control for the todo list. The proxy will require that that when a method call is made, the user making the call also be passed as an argument. Only if the user is the owner of the list or is one of the collaborators will the operation be performed.</p>
<img src="/2024/10/15/Low-Level-Design-1-Todo-List/todolist_proxy.png" class="">
<h2 id="Observer-Pattern"><a href="#Observer-Pattern" class="headerlink" title="Observer Pattern"></a><a target="_blank" rel="noopener" href="https://www.gofpattern.com/behavioral/patterns/observer-pattern.php">Observer Pattern</a></h2><p>The observer pattern allows objects, the observers, to be notified when the state of another object, the observable, changes. </p>
<img src="/2024/10/15/Low-Level-Design-1-Todo-List/observer_pattern.gif" class="">
<p>In our todolist example, we’ll create observers which get notified when the state of the todo list changes. We’ll create an abstract class called <code>Observable</code> which will be inherited by the <code>TodoList</code> class. This makes the class “observable”. We’ll create another class <code>TodoListObserver</code> which inherits the <code>Observer</code> class. This makes it the “observer” and it’ll be notified when changes happen to the todo list.</p>
<img src="/2024/10/15/Low-Level-Design-1-Todo-List/todolist_observer.png" class="">
<p>Now that we’ve looked at the design patterns we’ll use, let’s look at the code. </p>
<h1 id="Code"><a href="#Code" class="headerlink" title="Code"></a>Code</h1><h2 id="User"><a href="#User" class="headerlink" title="User"></a>User</h2><p>We’ll begin with the simplest class first, the <code>User</code> class which represents a user of the system. The owners and collaborators of the list will be represented by this class. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@dc.dataclass(<span class="params">frozen=<span class="literal">True</span></span>)</span></span><br><span class="line"><span class="keyword">class</span> <span class="title class_">User</span>:</span><br><span class="line"> email: <span class="built_in">str</span></span><br></pre></td></tr></table></figure>
<h2 id="Observer-Pattern-1"><a href="#Observer-Pattern-1" class="headerlink" title="Observer Pattern"></a>Observer Pattern</h2><p>Next, let’s add classes to create the observer pattern. We’ll begin by creating the abstract observable class. It’ll store the list of observers it has to notify, and require the subclasses to provide an implementation to return their state. Since the observers hold a reference to the observable they are observing, the method which returns the state will be used to find what’s changed. </p>
<p>The implementation for the <code>Observable</code> class is shown below. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@dc.dataclass(<span class="params">kw_only=<span class="literal">True</span></span>)</span></span><br><span class="line"><span class="keyword">class</span> <span class="title class_">Observable</span>(abc.ABC):</span><br><span class="line"> observers: <span class="built_in">list</span>[<span class="string">"Observer"</span>] = dc.field(default_factory=<span class="built_in">list</span>)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">notify</span>(<span class="params">self</span>):</span><br><span class="line"> <span class="keyword">for</span> observer <span class="keyword">in</span> self.observers:</span><br><span class="line"> observer.update()</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">add_observer</span>(<span class="params">self, observer: <span class="string">"Observer"</span></span>):</span><br><span class="line"> self.observers.append(observer)</span><br><span class="line"></span><br><span class="line"><span class="meta"> @property</span></span><br><span class="line"><span class="meta"> @abc.abstractmethod</span></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">state</span>(<span class="params">self</span>) -> typing.<span class="type">Any</span>: ...</span><br></pre></td></tr></table></figure>
<p>Similarly, we’ll implement the <code>Observer</code> class. It requires its subclasses to provide an implementation for the <code>update</code> method which will be called by the <code>Observable</code> it’s observing. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@dc.dataclass(<span class="params">kw_only=<span class="literal">True</span></span>)</span></span><br><span class="line"><span class="keyword">class</span> <span class="title class_">Observer</span>(abc.ABC):</span><br><span class="line"> observable: <span class="string">"Observable"</span></span><br><span class="line"></span><br><span class="line"><span class="meta"> @abc.abstractmethod</span></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">update</span>(<span class="params">self</span>): ...</span><br></pre></td></tr></table></figure>
<p>Finally, we’ll create the concrete observer <code>TodoListObserver</code>. It notifies the user by sending them an email when the list is updated. For simplicity, however, we’ll just log a message to the console. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">class</span> <span class="title class_">TodoListObserver</span>(<span class="title class_ inherited__">Observer</span>):</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">__init__</span>(<span class="params">self, user: <span class="string">"User"</span></span>):</span><br><span class="line"> self.user = user</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">update</span>(<span class="params">self</span>):</span><br><span class="line"> state = self.observable.state</span><br><span class="line"> <span class="built_in">print</span>(<span class="string">f"Notify <span class="subst">{self.user.email}</span> about changed state"</span>)</span><br></pre></td></tr></table></figure>
<h2 id="Composite-Pattern-1"><a href="#Composite-Pattern-1" class="headerlink" title="Composite Pattern"></a>Composite Pattern</h2><p>Next we’ll create the composite pattern. We’ll create a base class <code>TodoItem</code> which will be inherited by both the <code>Task</code> and <code>SubTask</code> class. It has basic fields that are required to define a task like an ID, a title, etc. and a couple of base methods to mark the item as complete or check if it’s complete.</p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@dc.dataclass(<span class="params">kw_only=<span class="literal">True</span></span>)</span></span><br><span class="line"><span class="keyword">class</span> <span class="title class_">TodoItem</span>(abc.ABC):</span><br><span class="line"> <span class="built_in">id</span>: uuid.UUID = dc.field(default_factory=uuid.uuid4)</span><br><span class="line"> title: <span class="built_in">str</span></span><br><span class="line"> completed: <span class="built_in">bool</span> = dc.field(default=<span class="literal">False</span>)</span><br><span class="line"></span><br><span class="line"><span class="meta"> @abc.abstractmethod</span></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">is_complete</span>(<span class="params">self</span>) -> <span class="built_in">bool</span>: ...</span><br><span class="line"></span><br><span class="line"><span class="meta"> @abc.abstractmethod</span></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">complete</span>(<span class="params">self</span>) -> <span class="literal">None</span>: ...</span><br></pre></td></tr></table></figure>
<p>The first of the subclasses is the <code>Task</code> class which we’ll implement next. A task is considered complete when it’s been marked completed and are all of its subtasks. Similarly, marking a task complete marks all the subtasks as complete.</p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@dc.dataclass(<span class="params">kw_only=<span class="literal">True</span></span>)</span></span><br><span class="line"><span class="keyword">class</span> <span class="title class_">Task</span>(<span class="title class_ inherited__">TodoItem</span>):</span><br><span class="line"> subtasks: <span class="built_in">list</span>[<span class="string">"SubTask"</span>] = dc.field(default_factory=<span class="built_in">list</span>)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">is_complete</span>(<span class="params">self</span>) -> <span class="built_in">bool</span>:</span><br><span class="line"> <span class="keyword">return</span> self.completed <span class="keyword">and</span> <span class="built_in">all</span>(subtask.completed <span class="keyword">for</span> subtask <span class="keyword">in</span> self.subtasks)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">complete</span>(<span class="params">self</span>):</span><br><span class="line"> self.completed = <span class="literal">True</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">for</span> subtask <span class="keyword">in</span> self.subtasks:</span><br><span class="line"> subtask.complete()</span><br><span class="line"></span><br><span class="line"> <span class="keyword">assert</span> self.is_complete() <span class="keyword">is</span> <span class="literal">True</span></span><br></pre></td></tr></table></figure>
<p>To complete the composite, we’ll add the <code>SubTask</code> class.</p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@dc.dataclass(<span class="params">kw_only=<span class="literal">True</span></span>)</span></span><br><span class="line"><span class="keyword">class</span> <span class="title class_">SubTask</span>(<span class="title class_ inherited__">TodoItem</span>):</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">is_complete</span>(<span class="params">self</span>) -> <span class="built_in">bool</span>:</span><br><span class="line"> <span class="keyword">return</span> self.completed</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">complete</span>(<span class="params">self</span>):</span><br><span class="line"> self.completed = <span class="literal">True</span></span><br></pre></td></tr></table></figure>
<p>If we look at the <code>TodoItem</code>, <code>Task</code>, <code>SubTask</code> classes, we can see the hierarchical structure where each <code>Task</code>, a non-leaf component, may have zero or more <code>SubTask</code>s, leaf components. Since both the <code>Task</code> and <code>SubTask</code> are instances of <code>TodoItem</code>, they have the same interface and can be used interchangeably. </p>
<h2 id="Adapter-Pattern-1"><a href="#Adapter-Pattern-1" class="headerlink" title="Adapter Pattern"></a>Adapter Pattern</h2><p>Next we’ll create a simple database adapter with a single method to save the todo list. There is only one method for the sake of simplicity but it’s easy to see how there can be more of these methods. We’ll start with a protocol called <code>DatabaseAdapter</code>. Think of a Python protocol to be similar to a Java interface.</p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">class</span> <span class="title class_">DatabaseAdapter</span>(<span class="title class_ inherited__">Protocol</span>):</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">save_list</span>(<span class="params">self, todolist: <span class="string">"TodoList"</span></span>): ...</span><br></pre></td></tr></table></figure>
<p>Next we’ll create two concrete classes which implement this protocol. The first class creates an adapter for MySQL and another for SQLite. Both of these classes take an instance of their specific database and use it to persist the todo list. Since each database instance may have its own set of methods to save data, an adapter provides a familiar interface that can be used elsewhere in the code.</p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">class</span> <span class="title class_">MySQLAdapter</span>(<span class="title class_ inherited__">DatabaseAdapter</span>):</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">__init__</span>(<span class="params">self, db</span>):</span><br><span class="line"> self.db = db</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">save_list</span>(<span class="params">self, todolist: <span class="string">"TodoList"</span></span>): ...</span><br><span class="line"></span><br><span class="line"></span><br><span class="line"><span class="keyword">class</span> <span class="title class_">SQLiteAdapter</span>(<span class="title class_ inherited__">DatabaseAdapter</span>):</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">__init__</span>(<span class="params">self, db</span>):</span><br><span class="line"> self.db = db</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">save_list</span>(<span class="params">self, todolist: <span class="string">"TodoList"</span></span>): ...</span><br></pre></td></tr></table></figure>
<h2 id="Strategy-Pattern-1"><a href="#Strategy-Pattern-1" class="headerlink" title="Strategy Pattern"></a>Strategy Pattern</h2><p>Next, we’ll create strategies to render the todo list. We’ll start by creating a protocol called <code>RenderingStratgy</code> with a single method called <code>render</code> which returns a string representation of the todo list. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">class</span> <span class="title class_">RenderingStrategy</span>(<span class="title class_ inherited__">Protocol</span>):</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">render</span>(<span class="params">self, todolist: <span class="string">"TodoList"</span></span>) -> <span class="built_in">str</span>: ...</span><br></pre></td></tr></table></figure>
<p>We’ll add a concrete strategy called <code>TableRenderingStrategy</code> which displays the tasks and subtasks in tabular format. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">class</span> <span class="title class_">TableRenderingStrategy</span>(<span class="title class_ inherited__">RenderingStrategy</span>):</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">render</span>(<span class="params">self, todolist: <span class="string">"TodoList"</span></span>) -> <span class="built_in">str</span>:</span><br><span class="line"> headers = [<span class="string">"Title"</span>, <span class="string">"Status"</span>]</span><br><span class="line"> tasks_and_subtasks = []</span><br><span class="line"></span><br><span class="line"> <span class="keyword">for</span> task <span class="keyword">in</span> todolist.tasks:</span><br><span class="line"> tasks_and_subtasks.append([task.title, task.is_complete()])</span><br><span class="line"></span><br><span class="line"> <span class="keyword">for</span> subtask <span class="keyword">in</span> task.subtasks:</span><br><span class="line"> tasks_and_subtasks.append(</span><br><span class="line"> [<span class="string">"-> "</span> + subtask.title, subtask.is_complete()]</span><br><span class="line"> )</span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> tabulate(tasks_and_subtasks, headers=headers)</span><br></pre></td></tr></table></figure>
<h2 id="Proxy-Pattern-1"><a href="#Proxy-Pattern-1" class="headerlink" title="Proxy Pattern"></a>Proxy Pattern</h2><p>To create the proxy pattern, we’ll create the protocol, <code>TodoListProtocol</code>, for both the todo list and the proxy. Let’s start with the protocol which defines the methods that are common to both the todo list and the proxy. As we can see, there’s methods to mark the list as complete, to search for tasks, to render the list, and so on. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">class</span> <span class="title class_">TodoListProtocol</span>(<span class="title class_ inherited__">Protocol</span>):</span><br><span class="line"><span class="meta"> @abc.abstractmethod</span></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">complete</span>(<span class="params">self, *args, **kwargs</span>): ...</span><br><span class="line"></span><br><span class="line"><span class="meta"> @abc.abstractmethod</span></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">search</span>(<span class="params">self, *args, **kwargs</span>) -> <span class="built_in">list</span>[Task]: ...</span><br><span class="line"></span><br><span class="line"><span class="meta"> @abc.abstractmethod</span></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">add</span>(<span class="params">self, *args, **kwargs</span>): ...</span><br><span class="line"></span><br><span class="line"><span class="meta"> @abc.abstractmethod</span></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">save</span>(<span class="params">self, *args, **kwargs</span>): ...</span><br><span class="line"></span><br><span class="line"><span class="meta"> @abc.abstractmethod</span></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">render</span>(<span class="params">self, *args, **kwargs</span>) -> <span class="built_in">str</span>: ...</span><br></pre></td></tr></table></figure>
<p>Next we’ll add the implementation for the <code>TodoList</code> which implemenets this protocol. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@dc.dataclass(<span class="params">kw_only=<span class="literal">True</span></span>)</span></span><br><span class="line"><span class="keyword">class</span> <span class="title class_">TodoList</span>(TodoListProtocol, Observable):</span><br><span class="line"> <span class="built_in">id</span>: uuid.UUID = dc.field(default_factory=uuid.uuid4)</span><br><span class="line"> title: <span class="built_in">str</span></span><br><span class="line"> tasks: <span class="built_in">list</span>[Task] = dc.field(default_factory=<span class="built_in">list</span>)</span><br><span class="line"> owner: User</span><br><span class="line"> collaborators: <span class="built_in">set</span>[User] = dc.field(default_factory=<span class="built_in">list</span>)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">complete</span>(<span class="params">self, *args, **kwargs</span>):</span><br><span class="line"> <span class="keyword">for</span> task <span class="keyword">in</span> self.tasks:</span><br><span class="line"> task.complete()</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">search</span>(<span class="params">self, title: <span class="built_in">str</span>, *args, **kwargs</span>) -> <span class="built_in">list</span>[Task]:</span><br><span class="line"> <span class="keyword">return</span> [task <span class="keyword">for</span> task <span class="keyword">in</span> self.tasks <span class="keyword">if</span> title.lower() <span class="keyword">in</span> task.title.lower()]</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">add</span>(<span class="params">self, task: Task, *args, **kwargs</span>):</span><br><span class="line"> self.tasks.append(task)</span><br><span class="line"> self.notify()</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">save</span>(<span class="params">self, adapter: DatabaseAdapter, *args, **kwargs</span>):</span><br><span class="line"> adapter.save_list(todolist=self)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">render</span>(<span class="params">self, strategy: RenderingStrategy, *args, **kwargs</span>) -> <span class="built_in">str</span>:</span><br><span class="line"> <span class="keyword">return</span> strategy.render(self)</span><br><span class="line"></span><br><span class="line"><span class="meta"> @property</span></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">state</span>(<span class="params">self</span>) -> <span class="built_in">list</span>[Task]:</span><br><span class="line"> <span class="keyword">return</span> copy.copy(self.tasks)</span><br></pre></td></tr></table></figure>
<p>Notice how it implements both <code>TodoListProtocol</code> and <code>Observable</code>. In the <code>add</code> method, we call <code>notify</code> which updates all the observers for this list. </p>
<p>Finally, we’ll add the proxy for <code>TodoList</code>. The proxy authenticates each call to the underlying <code>TodoList</code> by checking whether the user trying to access the list is the owner or a collaborator. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@dc.dataclass(<span class="params">kw_only=<span class="literal">True</span></span>)</span></span><br><span class="line"><span class="keyword">class</span> <span class="title class_">TodoListProxy</span>(<span class="title class_ inherited__">TodoListProtocol</span>):</span><br><span class="line"> todolist: TodoList</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">complete</span>(<span class="params">self, user: User, *args, **kwargs</span>):</span><br><span class="line"> self.raise_if_not_authenticated(user=user)</span><br><span class="line"> self.todolist.complete()</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">search</span>(<span class="params">self, title: <span class="built_in">str</span>, user: User, *args, **kwargs</span>) -> <span class="built_in">list</span>[Task]:</span><br><span class="line"> self.raise_if_not_authenticated(user=user)</span><br><span class="line"> <span class="keyword">return</span> self.todolist.search(title=title)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">add</span>(<span class="params">self, task: Task, user: User, *args, **kwargs</span>):</span><br><span class="line"> self.raise_if_not_authenticated(user=user)</span><br><span class="line"> self.todolist.add(task=task)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">save</span>(<span class="params">self, adapter: DatabaseAdapter, user: User, *args, **kwargs</span>):</span><br><span class="line"> self.raise_if_not_authenticated(user=user)</span><br><span class="line"> self.todolist.save(adapter=adapter)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">render</span>(<span class="params">self, strategy: RenderingStrategy, user: User, *args, **kwargs</span>) -> <span class="built_in">str</span>:</span><br><span class="line"> self.raise_if_not_authenticated(user=user)</span><br><span class="line"> <span class="keyword">return</span> self.todolist.render(strategy=strategy)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">raise_if_not_authenticated</span>(<span class="params">self, user: User</span>):</span><br><span class="line"> <span class="keyword">if</span> <span class="keyword">not</span> self.is_authenticated_user(user=user):</span><br><span class="line"> <span class="keyword">raise</span> Exception(<span class="string">f"User <span class="subst">{user.email}</span> is not authenticated."</span>)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">def</span> <span class="title function_">is_authenticated_user</span>(<span class="params">self, user: User</span>):</span><br><span class="line"> <span class="keyword">return</span> (self.todolist.owner == user) <span class="keyword">or</span> (user <span class="keyword">in</span> self.todolist.collaborators)</span><br></pre></td></tr></table></figure>
<h1 id="Running-the-Code"><a href="#Running-the-Code" class="headerlink" title="Running the Code"></a>Running the Code</h1><p>Let’s wire the pieces together and run them. We’ll create an adapter, a rendering strategy, and an observer. Since we’ll use dependency injection, we’ll pass these obhects to the appropriate methods. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line">adapter: DatabaseAdapter = MySQLAdapter(db={})</span><br><span class="line">strategy: RenderingStrategy = TableRenderingStrategy()</span><br><span class="line">observer: Observer = TodoListObserver(user=User(email=<span class="string">"[email protected]"</span>))</span><br></pre></td></tr></table></figure>
<p>Next, let’s create the todo list itself. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br></pre></td><td class="code"><pre><span class="line">todolist = TodoList(</span><br><span class="line"> title=<span class="string">"..."</span>,</span><br><span class="line"> owner=User(<span class="string">"[email protected]"</span>),</span><br><span class="line"> collaborators={</span><br><span class="line"> User(<span class="string">"[email protected]"</span>),</span><br><span class="line"> },</span><br><span class="line"> tasks=[</span><br><span class="line"> Task(</span><br><span class="line"> title=<span class="string">"Get Groceries"</span>,</span><br><span class="line"> subtasks=[</span><br><span class="line"> SubTask(title=<span class="string">"Get Apples"</span>),</span><br><span class="line"> SubTask(title=<span class="string">"Get Bananas"</span>),</span><br><span class="line"> ],</span><br><span class="line"> ),</span><br><span class="line"> Task(</span><br><span class="line"> title=<span class="string">"Do laundry"</span>,</span><br><span class="line"> completed=<span class="literal">False</span>,</span><br><span class="line"> ),</span><br><span class="line"> ],</span><br><span class="line"> observers=[</span><br><span class="line"> observer,</span><br><span class="line"> ],</span><br><span class="line"> )</span><br></pre></td></tr></table></figure>
<p>Notice we’ve added tasks and subtasks to the list. We’ve also added a collaborator and an observer to the list. We’ll finish adding the observer by updating its <code>observable</code> property. This will allow it to fetch the state from the list when it gets updated. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">observer.observable = todolist</span><br></pre></td></tr></table></figure>
<p>Next, we’ll create a proxy for the list so that we can authenticate the calls. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">proxy = TodoListProxy(todolist=todolist)</span><br></pre></td></tr></table></figure>
<p>We can now make method calls to see the code in action. Let’s begin by adding a task. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">proxy.add(</span><br><span class="line"> task=Task(title=<span class="string">"Walk the dog"</span>),</span><br><span class="line"> user=User(<span class="string">"[email protected]"</span>),</span><br><span class="line">)</span><br></pre></td></tr></table></figure>
<p>This produces the following output in the console. Since John Doe added an item to the list, Jane Doe will be notified of the change.</p>
<figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">Notify [email protected] about changed state</span><br></pre></td></tr></table></figure>
<p>Next, we’ll render the list. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="built_in">print</span>(</span><br><span class="line"> proxy.render(</span><br><span class="line"> strategy=strategy,</span><br><span class="line"> user=User(<span class="string">"[email protected]"</span>),</span><br><span class="line"> )</span><br><span class="line">)</span><br></pre></td></tr></table></figure>
<p>The list is rendered as follows. The subtasks are marked with an arrow to indicate a level of nesting. </p>
<figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line">Title Status</span><br><span class="line">-------------- --------</span><br><span class="line">Get Groceries False</span><br><span class="line">-> Get Apples False</span><br><span class="line">-> Get Bananas False</span><br><span class="line">Do laundry False</span><br><span class="line">Walk the dog False</span><br></pre></td></tr></table></figure>
<p>Finally, we’ll make an unauthenticated call to see proxy in action. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">proxy.add(</span><br><span class="line"> task=Task(title=<span class="string">"Walk the dog"</span>),</span><br><span class="line"> user=User(<span class="string">"..."</span>),</span><br><span class="line">)</span><br></pre></td></tr></table></figure>
<p>This raises an exception saying that the user is not authenticated. </p>
<p>That’s it. That’s how to create a todo list.</p>
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<article id="post-Detecting-disguised-email-addresses-in-a-corpus-of-text" class="article article-type-post" itemscope itemprop="blogPost">
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<time datetime="2024-08-03T06:08:36.000Z" itemprop="datePublished">2024-08-03</time>
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<a class="article-title" href="/2024/08/03/Detecting-disguised-email-addresses-in-a-corpus-of-text/">Detecting disguised email addresses in a corpus of text</a>
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<p>I’d recently written about <a href="/2024/08/02/An-experiemental-library-to-detect-PII/">an experimental library to detect PII.</a> When discussing it with an acquaintance of mine, I was told that PII can also be disguised. For example, a corpus of text like a review or a comment can contain email address in the form “johndoeatgmaildotcom”. This led me to update the library so that emails like these can also be flagged. In a nutshell, I had to update the regex which was used to find the email. </p>
<h2 id="Example"><a href="#Example" class="headerlink" title="Example"></a>Example</h2><p>This is best explained with a few examples. In all of the examples, we begin with a proper email and disguise it one step at a time.</p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line">column = Column(name=<span class="string">"comment"</span>)</span><br><span class="line">detector = ColumnValueRegexDetector()</span><br><span class="line"></span><br><span class="line"><span class="keyword">assert</span> detector.detect(column=column, sample=<span class="string">"[email protected]"</span>) == Email()</span><br><span class="line"><span class="keyword">assert</span> detector.detect(column=column, sample=<span class="string">"[email protected]"</span>) == Email()</span><br><span class="line"><span class="keyword">assert</span> detector.detect(column=column, sample=<span class="string">"johndotdoeatproviderdotcom"</span>) == Email()</span><br><span class="line"><span class="keyword">assert</span> detector.detect(column=column, sample=<span class="string">"[email protected]"</span>) == Email()</span><br><span class="line"><span class="keyword">assert</span> detector.detect(column=column, sample=<span class="string">"johndotdoeatproviderdotcodotuk"</span>) == Email()</span><br><span class="line"><span class="keyword">assert</span> detector.detect(column=column, sample=<span class="string">"myemailis:john.doeatproviderdotcom"</span>) == Email()</span><br></pre></td></tr></table></figure>
<p>All of these assertions pass and the regex detector is able to flag all of these examples as email.</p>
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<article id="post-An-experiemental-library-to-detect-PII" class="article article-type-post" itemscope itemprop="blogPost">
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<time datetime="2024-08-02T06:36:13.000Z" itemprop="datePublished">2024-08-02</time>
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<a class="article-title" href="/2024/08/02/An-experiemental-library-to-detect-PII/">An experiemental library to detect PII</a>
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<p>I recently created an experimental library, <a target="_blank" rel="noopener" href="https://github.com/thescalaguy/detectpii">detectpii</a>, to detect PII data in relational databases. In this post we’ll take a look at the rationale behind the library and it’s architecture. </p>
<h2 id="Rationale"><a href="#Rationale" class="headerlink" title="Rationale"></a>Rationale</h2><p>A common requirement in many software systems is to store PII information. For example, a food ordering system may store the user’s name, address, phone number, and email. This information may also be replicated into the data warehouse. As a matter of good data governance, you may want to restrict access to such information. Many data warehouses allow applying a masking policy that makes it easier to redact such values. However, you’d have to specify which columns to apply this policy to. detectpii makes it easier to identify such tables and columns. </p>
<p>My journey into creating this library began by looking for open-source projects that would help identify such information. After some research, I did find a few projects that do this. The first project is <a target="_blank" rel="noopener" href="https://github.com/tokern/piicatcher">piicatcher</a>. It allows comparing the column names of tables against regular expressions that represent common PII column names like user_name. The second project is <a target="_blank" rel="noopener" href="https://github.com/madisonmay/CommonRegex">CommonRegex</a> which allows comparing column values against regular expression patterns like emails, IP addresses, etc. </p>
<p>detectpii combines these two libraries to allow finding column names and values that may potentially contain PII. Out of the box, the library allows scanning column names and a subset of its values for potentially PII information.</p>
<h2 id="Architecure"><a href="#Architecure" class="headerlink" title="Architecure"></a>Architecure</h2><img src="/2024/08/02/An-experiemental-library-to-detect-PII/detectpii.png" class="">
<p>At the heart of the library is the <code>PiiDetectionPipeline</code>. A pipeline consists of a <code>Catalog</code>, which represents the database we’d like to scan, and a number of <code>Scanner</code>s, which perform the actual scan. The library ships with two scanners - the <code>MetadataScanner</code> and the <code>DataScanner</code>. The first compares column names of the tables in the catalog against known patterns for the ones which store PII information. The second compares the value of each column of the table by retrieving a subset of the rows and comparing them against patterns for PII. The result of the scan is a list of column names that may potentially be PII. </p>
<p>The design of the library is extensible and more scanners can be added. For example, a scanner to use a proprietary machine learning algorithm instead of regular expression match.</p>
<h2 id="Usage"><a href="#Usage" class="headerlink" title="Usage"></a>Usage</h2><p>To perform a scan, we create a pipeline and pass it a catalog and a list of scanners. To inititate the scan, we call the <code>scan</code> method on the pipeline to get back a list of PII columns.</p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">from</span> detectpii.catalog <span class="keyword">import</span> PostgresCatalog</span><br><span class="line"><span class="keyword">from</span> detectpii.pipeline <span class="keyword">import</span> PiiDetectionPipeline</span><br><span class="line"><span class="keyword">from</span> detectpii.scanner <span class="keyword">import</span> DataScanner, MetadataScanner</span><br><span class="line"></span><br><span class="line"><span class="comment"># -- Create a catalog to connect to a database / warehouse</span></span><br><span class="line">pg_catalog = PostgresCatalog(</span><br><span class="line"> host=<span class="string">"localhost"</span>,</span><br><span class="line"> user=<span class="string">"postgres"</span>,</span><br><span class="line"> password=<span class="string">"my-secret-pw"</span>,</span><br><span class="line"> database=<span class="string">"postgres"</span>,</span><br><span class="line"> port=<span class="number">5432</span>,</span><br><span class="line"> schema=<span class="string">"public"</span></span><br><span class="line">)</span><br><span class="line"></span><br><span class="line"><span class="comment"># -- Create a pipeline to detect PII in the tables</span></span><br><span class="line">pipeline = PiiDetectionPipeline(</span><br><span class="line"> catalog=pg_catalog,</span><br><span class="line"> scanners=[</span><br><span class="line"> MetadataScanner(),</span><br><span class="line"> DataScanner(percentage=<span class="number">20</span>, times=<span class="number">2</span>,),</span><br><span class="line"> ]</span><br><span class="line">)</span><br><span class="line"></span><br><span class="line"><span class="comment"># -- Scan for PII columns.</span></span><br><span class="line">pii_columns = pipeline.scan()</span><br></pre></td></tr></table></figure>
<p>That’s it. That’s how to use the library to detect PII columns in tables.</p>
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<article id="post-A-question-on-algebraic-manipulations" class="article article-type-post" itemscope itemprop="blogPost">
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<a href="/2024/07/23/A-question-on-algebraic-manipulations/" class="article-date">
<time datetime="2024-07-23T06:49:29.000Z" itemprop="datePublished">2024-07-23</time>
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<a class="article-title" href="/2024/07/23/A-question-on-algebraic-manipulations/">A question on algebraic manipulations</a>
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<div class="article-entry" itemprop="articleBody">
<p>In the exercises that follow the chapter on algebraic manipulations, there is a question that pertains to expressing an integer <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.439ex;" xmlns="http://www.w3.org/2000/svg" width="1.041ex" height="1.439ex" role="img" focusable="false" viewBox="0 -442 460 636"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D45E" d="M33 157Q33 258 109 349T280 441Q340 441 372 389Q373 390 377 395T388 406T404 418Q438 442 450 442Q454 442 457 439T460 434Q460 425 391 149Q320 -135 320 -139Q320 -147 365 -148H390Q396 -156 396 -157T393 -175Q389 -188 383 -194H370Q339 -192 262 -192Q234 -192 211 -192T174 -192T157 -193Q143 -193 143 -185Q143 -182 145 -170Q149 -154 152 -151T172 -148Q220 -148 230 -141Q238 -136 258 -53T279 32Q279 33 272 29Q224 -10 172 -10Q117 -10 75 30T33 157ZM352 326Q329 405 277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q233 26 290 98L298 109L352 326Z"></path></g></g></g></svg></mjx-container> as the sum of two other integers squared. We are then asked to find expressions for the multiples of <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.439ex;" xmlns="http://www.w3.org/2000/svg" width="1.041ex" height="1.439ex" role="img" focusable="false" viewBox="0 -442 460 636"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D45E" d="M33 157Q33 258 109 349T280 441Q340 441 372 389Q373 390 377 395T388 406T404 418Q438 442 450 442Q454 442 457 439T460 434Q460 425 391 149Q320 -135 320 -139Q320 -147 365 -148H390Q396 -156 396 -157T393 -175Q389 -188 383 -194H370Q339 -192 262 -192Q234 -192 211 -192T174 -192T157 -193Q143 -193 143 -185Q143 -182 145 -170Q149 -154 152 -151T172 -148Q220 -148 230 -141Q238 -136 258 -53T279 32Q279 33 272 29Q224 -10 172 -10Q117 -10 75 30T33 157ZM352 326Q329 405 277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q233 26 290 98L298 109L352 326Z"></path></g></g></g></svg></mjx-container>, namely <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.439ex;" xmlns="http://www.w3.org/2000/svg" width="2.172ex" height="1.946ex" role="img" focusable="false" viewBox="0 -666 960 860"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="mi" transform="translate(500,0)"><path data-c="1D45E" d="M33 157Q33 258 109 349T280 441Q340 441 372 389Q373 390 377 395T388 406T404 418Q438 442 450 442Q454 442 457 439T460 434Q460 425 391 149Q320 -135 320 -139Q320 -147 365 -148H390Q396 -156 396 -157T393 -175Q389 -188 383 -194H370Q339 -192 262 -192Q234 -192 211 -192T174 -192T157 -193Q143 -193 143 -185Q143 -182 145 -170Q149 -154 152 -151T172 -148Q220 -148 230 -141Q238 -136 258 -53T279 32Q279 33 272 29Q224 -10 172 -10Q117 -10 75 30T33 157ZM352 326Q329 405 277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q233 26 290 98L298 109L352 326Z"></path></g></g></g></svg></mjx-container> and <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.439ex;" xmlns="http://www.w3.org/2000/svg" width="2.172ex" height="1.946ex" role="img" focusable="false" viewBox="0 -666 960 860"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="35" d="M164 157Q164 133 148 117T109 101H102Q148 22 224 22Q294 22 326 82Q345 115 345 210Q345 313 318 349Q292 382 260 382H254Q176 382 136 314Q132 307 129 306T114 304Q97 304 95 310Q93 314 93 485V614Q93 664 98 664Q100 666 102 666Q103 666 123 658T178 642T253 634Q324 634 389 662Q397 666 402 666Q410 666 410 648V635Q328 538 205 538Q174 538 149 544L139 546V374Q158 388 169 396T205 412T256 420Q337 420 393 355T449 201Q449 109 385 44T229 -22Q148 -22 99 32T50 154Q50 178 61 192T84 210T107 214Q132 214 148 197T164 157Z"></path></g><g data-mml-node="mi" transform="translate(500,0)"><path data-c="1D45E" d="M33 157Q33 258 109 349T280 441Q340 441 372 389Q373 390 377 395T388 406T404 418Q438 442 450 442Q454 442 457 439T460 434Q460 425 391 149Q320 -135 320 -139Q320 -147 365 -148H390Q396 -156 396 -157T393 -175Q389 -188 383 -194H370Q339 -192 262 -192Q234 -192 211 -192T174 -192T157 -193Q143 -193 143 -185Q143 -182 145 -170Q149 -154 152 -151T172 -148Q220 -148 230 -141Q238 -136 258 -53T279 32Q279 33 272 29Q224 -10 172 -10Q117 -10 75 30T33 157ZM352 326Q329 405 277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q233 26 290 98L298 109L352 326Z"></path></g></g></g></svg></mjx-container>. In this post, we’ll take a look at the solution provided by the authors for the first half of the question, <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.439ex;" xmlns="http://www.w3.org/2000/svg" width="2.172ex" height="1.946ex" role="img" focusable="false" viewBox="0 -666 960 860"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="mi" transform="translate(500,0)"><path data-c="1D45E" d="M33 157Q33 258 109 349T280 441Q340 441 372 389Q373 390 377 395T388 406T404 418Q438 442 450 442Q454 442 457 439T460 434Q460 425 391 149Q320 -135 320 -139Q320 -147 365 -148H390Q396 -156 396 -157T393 -175Q389 -188 383 -194H370Q339 -192 262 -192Q234 -192 211 -192T174 -192T157 -193Q143 -193 143 -185Q143 -182 145 -170Q149 -154 152 -151T172 -148Q220 -148 230 -141Q238 -136 258 -53T279 32Q279 33 272 29Q224 -10 172 -10Q117 -10 75 30T33 157ZM352 326Q329 405 277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q233 26 290 98L298 109L352 326Z"></path></g></g></g></svg></mjx-container>, and then come up with a method of our own to solve the second half, <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.439ex;" xmlns="http://www.w3.org/2000/svg" width="2.172ex" height="1.946ex" role="img" focusable="false" viewBox="0 -666 960 860"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="35" d="M164 157Q164 133 148 117T109 101H102Q148 22 224 22Q294 22 326 82Q345 115 345 210Q345 313 318 349Q292 382 260 382H254Q176 382 136 314Q132 307 129 306T114 304Q97 304 95 310Q93 314 93 485V614Q93 664 98 664Q100 666 102 666Q103 666 123 658T178 642T253 634Q324 634 389 662Q397 666 402 666Q410 666 410 648V635Q328 538 205 538Q174 538 149 544L139 546V374Q158 388 169 396T205 412T256 420Q337 420 393 355T449 201Q449 109 385 44T229 -22Q148 -22 99 32T50 154Q50 178 61 192T84 210T107 214Q132 214 148 197T164 157Z"></path></g><g data-mml-node="mi" transform="translate(500,0)"><path data-c="1D45E" d="M33 157Q33 258 109 349T280 441Q340 441 372 389Q373 390 377 395T388 406T404 418Q438 442 450 442Q454 442 457 439T460 434Q460 425 391 149Q320 -135 320 -139Q320 -147 365 -148H390Q396 -156 396 -157T393 -175Q389 -188 383 -194H370Q339 -192 262 -192Q234 -192 211 -192T174 -192T157 -193Q143 -193 143 -185Q143 -182 145 -170Q149 -154 152 -151T172 -148Q220 -148 230 -141Q238 -136 258 -53T279 32Q279 33 272 29Q224 -10 172 -10Q117 -10 75 30T33 157ZM352 326Q329 405 277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q233 26 290 98L298 109L352 326Z"></path></g></g></g></svg></mjx-container>. </p>
<h2 id="Question"><a href="#Question" class="headerlink" title="Question"></a>Question</h2><p>If <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.439ex;" xmlns="http://www.w3.org/2000/svg" width="1.041ex" height="1.439ex" role="img" focusable="false" viewBox="0 -442 460 636"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D45E" d="M33 157Q33 258 109 349T280 441Q340 441 372 389Q373 390 377 395T388 406T404 418Q438 442 450 442Q454 442 457 439T460 434Q460 425 391 149Q320 -135 320 -139Q320 -147 365 -148H390Q396 -156 396 -157T393 -175Q389 -188 383 -194H370Q339 -192 262 -192Q234 -192 211 -192T174 -192T157 -193Q143 -193 143 -185Q143 -182 145 -170Q149 -154 152 -151T172 -148Q220 -148 230 -141Q238 -136 258 -53T279 32Q279 33 272 29Q224 -10 172 -10Q117 -10 75 30T33 157ZM352 326Q329 405 277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q233 26 290 98L298 109L352 326Z"></path></g></g></g></svg></mjx-container> is an integer that can be expressed as the sum of two integer squares, show that both <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.439ex;" xmlns="http://www.w3.org/2000/svg" width="2.172ex" height="1.946ex" role="img" focusable="false" viewBox="0 -666 960 860"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="mi" transform="translate(500,0)"><path data-c="1D45E" d="M33 157Q33 258 109 349T280 441Q340 441 372 389Q373 390 377 395T388 406T404 418Q438 442 450 442Q454 442 457 439T460 434Q460 425 391 149Q320 -135 320 -139Q320 -147 365 -148H390Q396 -156 396 -157T393 -175Q389 -188 383 -194H370Q339 -192 262 -192Q234 -192 211 -192T174 -192T157 -193Q143 -193 143 -185Q143 -182 145 -170Q149 -154 152 -151T172 -148Q220 -148 230 -141Q238 -136 258 -53T279 32Q279 33 272 29Q224 -10 172 -10Q117 -10 75 30T33 157ZM352 326Q329 405 277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q233 26 290 98L298 109L352 326Z"></path></g></g></g></svg></mjx-container> and <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.439ex;" xmlns="http://www.w3.org/2000/svg" width="2.172ex" height="1.946ex" role="img" focusable="false" viewBox="0 -666 960 860"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="35" d="M164 157Q164 133 148 117T109 101H102Q148 22 224 22Q294 22 326 82Q345 115 345 210Q345 313 318 349Q292 382 260 382H254Q176 382 136 314Q132 307 129 306T114 304Q97 304 95 310Q93 314 93 485V614Q93 664 98 664Q100 666 102 666Q103 666 123 658T178 642T253 634Q324 634 389 662Q397 666 402 666Q410 666 410 648V635Q328 538 205 538Q174 538 149 544L139 546V374Q158 388 169 396T205 412T256 420Q337 420 393 355T449 201Q449 109 385 44T229 -22Q148 -22 99 32T50 154Q50 178 61 192T84 210T107 214Q132 214 148 197T164 157Z"></path></g><g data-mml-node="mi" transform="translate(500,0)"><path data-c="1D45E" d="M33 157Q33 258 109 349T280 441Q340 441 372 389Q373 390 377 395T388 406T404 418Q438 442 450 442Q454 442 457 439T460 434Q460 425 391 149Q320 -135 320 -139Q320 -147 365 -148H390Q396 -156 396 -157T393 -175Q389 -188 383 -194H370Q339 -192 262 -192Q234 -192 211 -192T174 -192T157 -193Q143 -193 143 -185Q143 -182 145 -170Q149 -154 152 -151T172 -148Q220 -148 230 -141Q238 -136 258 -53T279 32Q279 33 272 29Q224 -10 172 -10Q117 -10 75 30T33 157ZM352 326Q329 405 277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q233 26 290 98L298 109L352 326Z"></path></g></g></g></svg></mjx-container> can also be expressed as the sum of two integer squares. </p>
<h2 id="Solution"><a href="#Solution" class="headerlink" title="Solution"></a>Solution</h2><p>From the question, <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.439ex;" xmlns="http://www.w3.org/2000/svg" width="10.966ex" height="2.326ex" role="img" focusable="false" viewBox="0 -833.9 4847.1 1027.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D45E" d="M33 157Q33 258 109 349T280 441Q340 441 372 389Q373 390 377 395T388 406T404 418Q438 442 450 442Q454 442 457 439T460 434Q460 425 391 149Q320 -135 320 -139Q320 -147 365 -148H390Q396 -156 396 -157T393 -175Q389 -188 383 -194H370Q339 -192 262 -192Q234 -192 211 -192T174 -192T157 -193Q143 -193 143 -185Q143 -182 145 -170Q149 -154 152 -151T172 -148Q220 -148 230 -141Q238 -136 258 -53T279 32Q279 33 272 29Q224 -10 172 -10Q117 -10 75 30T33 157ZM352 326Q329 405 277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q233 26 290 98L298 109L352 326Z"></path></g><g data-mml-node="mo" transform="translate(737.8,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="msup" transform="translate(1793.6,0)"><g data-mml-node="mi"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 328Z"></path></g><g data-mml-node="mn" transform="translate(562,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g><g data-mml-node="mo" transform="translate(2981.3,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="msup" transform="translate(3981.6,0)"><g data-mml-node="mi"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="mn" transform="translate(462,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g></g></g></svg></mjx-container> since it is the sum of two integer squares. This means <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="27.177ex" height="2.452ex" role="img" focusable="false" viewBox="0 -833.9 12012.2 1083.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="mi" transform="translate(500,0)"><path data-c="1D45E" d="M33 157Q33 258 109 349T280 441Q340 441 372 389Q373 390 377 395T388 406T404 418Q438 442 450 442Q454 442 457 439T460 434Q460 425 391 149Q320 -135 320 -139Q320 -147 365 -148H390Q396 -156 396 -157T393 -175Q389 -188 383 -194H370Q339 -192 262 -192Q234 -192 211 -192T174 -192T157 -193Q143 -193 143 -185Q143 -182 145 -170Q149 -154 152 -151T172 -148Q220 -148 230 -141Q238 -136 258 -53T279 32Q279 33 272 29Q224 -10 172 -10Q117 -10 75 30T33 157ZM352 326Q329 405 277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q233 26 290 98L298 109L352 326Z"></path></g><g data-mml-node="mo" transform="translate(1237.8,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mn" transform="translate(2293.6,0)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="mo" transform="translate(2793.6,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="msup" transform="translate(3182.6,0)"><g data-mml-node="mi"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 328Z"></path></g><g data-mml-node="mn" transform="translate(562,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g><g data-mml-node="mo" transform="translate(4370.3,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="msup" transform="translate(5370.6,0)"><g data-mml-node="mi"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="mn" transform="translate(462,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g><g data-mml-node="mo" transform="translate(6236.1,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="mo" transform="translate(6902.9,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mn" transform="translate(7958.7,0)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="msup" transform="translate(8458.7,0)"><g data-mml-node="mi"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 328Z"></path></g><g data-mml-node="mn" transform="translate(562,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g><g data-mml-node="mo" transform="translate(9646.4,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mn" transform="translate(10646.7,0)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="msup" transform="translate(11146.7,0)"><g data-mml-node="mi"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="mn" transform="translate(462,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g></g></g></svg></mjx-container>. We need to find two integers such that when their squares are summed, we end with <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.439ex;" xmlns="http://www.w3.org/2000/svg" width="2.172ex" height="1.946ex" role="img" focusable="false" viewBox="0 -666 960 860"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="mi" transform="translate(500,0)"><path data-c="1D45E" d="M33 157Q33 258 109 349T280 441Q340 441 372 389Q373 390 377 395T388 406T404 418Q438 442 450 442Q454 442 457 439T460 434Q460 425 391 149Q320 -135 320 -139Q320 -147 365 -148H390Q396 -156 396 -157T393 -175Q389 -188 383 -194H370Q339 -192 262 -192Q234 -192 211 -192T174 -192T157 -193Q143 -193 143 -185Q143 -182 145 -170Q149 -154 152 -151T172 -148Q220 -148 230 -141Q238 -136 258 -53T279 32Q279 33 272 29Q224 -10 172 -10Q117 -10 75 30T33 157ZM352 326Q329 405 277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q233 26 290 98L298 109L352 326Z"></path></g></g></g></svg></mjx-container>. From the solution, these are the numbers (a + b) and (a - b) because when they are squared and summed, we get <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="9.171ex" height="2.072ex" role="img" focusable="false" viewBox="0 -833.9 4053.6 915.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="msup" transform="translate(500,0)"><g data-mml-node="mi"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 328Z"></path></g><g data-mml-node="mn" transform="translate(562,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g><g data-mml-node="mo" transform="translate(1687.8,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mn" transform="translate(2688,0)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="msup" transform="translate(3188,0)"><g data-mml-node="mi"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="mn" transform="translate(462,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g></g></g></svg></mjx-container>. This is the result of <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="18.128ex" height="2.452ex" role="img" focusable="false" viewBox="0 -833.9 8012.4 1083.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mo"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(389,0)"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 328Z"></path></g><g data-mml-node="mo" transform="translate(1140.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(2140.4,0)"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="msup" transform="translate(2569.4,0)"><g data-mml-node="mo"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="mn" transform="translate(422,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g><g data-mml-node="mo" transform="translate(3617.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mo" transform="translate(4617.4,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(5006.4,0)"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 328Z"></path></g><g data-mml-node="mo" transform="translate(5757.7,0)"><path data-c="2212" d="M84 237T84 250T98 270H679Q694 262 694 250T679 230H98Q84 237 84 250Z"></path></g><g data-mml-node="mi" transform="translate(6757.9,0)"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="msup" transform="translate(7186.9,0)"><g data-mml-node="mo"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="mn" transform="translate(422,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g></g></g></svg></mjx-container>. Go ahead and expand them to verify the result. </p>
<p>What do we deduce from this? We find that both the expressions contributed an <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.023ex;" xmlns="http://www.w3.org/2000/svg" width="2.185ex" height="1.909ex" role="img" focusable="false" viewBox="0 -833.9 965.6 843.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="msup"><g data-mml-node="mi"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 328Z"></path></g><g data-mml-node="mn" transform="translate(562,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g></g></g></svg></mjx-container> and a <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.958ex" height="1.912ex" role="img" focusable="false" viewBox="0 -833.9 865.6 844.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="msup"><g data-mml-node="mi"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="mn" transform="translate(462,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g></g></g></svg></mjx-container>. These were added together to get the final result. How do we use this to get <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.439ex;" xmlns="http://www.w3.org/2000/svg" width="14.36ex" height="2.326ex" role="img" focusable="false" viewBox="0 -833.9 6347.1 1027.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="35" d="M164 157Q164 133 148 117T109 101H102Q148 22 224 22Q294 22 326 82Q345 115 345 210Q345 313 318 349Q292 382 260 382H254Q176 382 136 314Q132 307 129 306T114 304Q97 304 95 310Q93 314 93 485V614Q93 664 98 664Q100 666 102 666Q103 666 123 658T178 642T253 634Q324 634 389 662Q397 666 402 666Q410 666 410 648V635Q328 538 205 538Q174 538 149 544L139 546V374Q158 388 169 396T205 412T256 420Q337 420 393 355T449 201Q449 109 385 44T229 -22Q148 -22 99 32T50 154Q50 178 61 192T84 210T107 214Q132 214 148 197T164 157Z"></path></g><g data-mml-node="mi" transform="translate(500,0)"><path data-c="1D45E" d="M33 157Q33 258 109 349T280 441Q340 441 372 389Q373 390 377 395T388 406T404 418Q438 442 450 442Q454 442 457 439T460 434Q460 425 391 149Q320 -135 320 -139Q320 -147 365 -148H390Q396 -156 396 -157T393 -175Q389 -188 383 -194H370Q339 -192 262 -192Q234 -192 211 -192T174 -192T157 -193Q143 -193 143 -185Q143 -182 145 -170Q149 -154 152 -151T172 -148Q220 -148 230 -141Q238 -136 258 -53T279 32Q279 33 272 29Q224 -10 172 -10Q117 -10 75 30T33 157ZM352 326Q329 405 277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q233 26 290 98L298 109L352 326Z"></path></g><g data-mml-node="mo" transform="translate(1237.8,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mn" transform="translate(2293.6,0)"><path data-c="35" d="M164 157Q164 133 148 117T109 101H102Q148 22 224 22Q294 22 326 82Q345 115 345 210Q345 313 318 349Q292 382 260 382H254Q176 382 136 314Q132 307 129 306T114 304Q97 304 95 310Q93 314 93 485V614Q93 664 98 664Q100 666 102 666Q103 666 123 658T178 642T253 634Q324 634 389 662Q397 666 402 666Q410 666 410 648V635Q328 538 205 538Q174 538 149 544L139 546V374Q158 388 169 396T205 412T256 420Q337 420 393 355T449 201Q449 109 385 44T229 -22Q148 -22 99 32T50 154Q50 178 61 192T84 210T107 214Q132 214 148 197T164 157Z"></path></g><g data-mml-node="msup" transform="translate(2793.6,0)"><g data-mml-node="mi"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 328Z"></path></g><g data-mml-node="mn" transform="translate(562,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g><g data-mml-node="mo" transform="translate(3981.3,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mn" transform="translate(4981.6,0)"><path data-c="35" d="M164 157Q164 133 148 117T109 101H102Q148 22 224 22Q294 22 326 82Q345 115 345 210Q345 313 318 349Q292 382 260 382H254Q176 382 136 314Q132 307 129 306T114 304Q97 304 95 310Q93 314 93 485V614Q93 664 98 664Q100 666 102 666Q103 666 123 658T178 642T253 634Q324 634 389 662Q397 666 402 666Q410 666 410 648V635Q328 538 205 538Q174 538 149 544L139 546V374Q158 388 169 396T205 412T256 420Q337 420 393 355T449 201Q449 109 385 44T229 -22Q148 -22 99 32T50 154Q50 178 61 192T84 210T107 214Q132 214 148 197T164 157Z"></path></g><g data-mml-node="msup" transform="translate(5481.6,0)"><g data-mml-node="mi"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="mn" transform="translate(462,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g></g></g></svg></mjx-container>? Notice that we’re squaring the integers. This means that, for example, one of them would have to contribute an <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.023ex;" xmlns="http://www.w3.org/2000/svg" width="2.185ex" height="1.909ex" role="img" focusable="false" viewBox="0 -833.9 965.6 843.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="msup"><g data-mml-node="mi"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 328Z"></path></g><g data-mml-node="mn" transform="translate(562,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g></g></g></svg></mjx-container> and the other would have to contribute a <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.023ex;" xmlns="http://www.w3.org/2000/svg" width="3.316ex" height="1.909ex" role="img" focusable="false" viewBox="0 -833.9 1465.6 843.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="34" d="M462 0Q444 3 333 3Q217 3 199 0H190V46H221Q241 46 248 46T265 48T279 53T286 61Q287 63 287 115V165H28V211L179 442Q332 674 334 675Q336 677 355 677H373L379 671V211H471V165H379V114Q379 73 379 66T385 54Q393 47 442 46H471V0H462ZM293 211V545L74 212L183 211H293Z"></path></g><g data-mml-node="msup" transform="translate(500,0)"><g data-mml-node="mi"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 328Z"></path></g><g data-mml-node="mn" transform="translate(562,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g></g></g></svg></mjx-container>; similar logic applies for <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.05ex;" xmlns="http://www.w3.org/2000/svg" width="3.089ex" height="1.937ex" role="img" focusable="false" viewBox="0 -833.9 1365.6 855.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="35" d="M164 157Q164 133 148 117T109 101H102Q148 22 224 22Q294 22 326 82Q345 115 345 210Q345 313 318 349Q292 382 260 382H254Q176 382 136 314Q132 307 129 306T114 304Q97 304 95 310Q93 314 93 485V614Q93 664 98 664Q100 666 102 666Q103 666 123 658T178 642T253 634Q324 634 389 662Q397 666 402 666Q410 666 410 648V635Q328 538 205 538Q174 538 149 544L139 546V374Q158 388 169 396T205 412T256 420Q337 420 393 355T449 201Q449 109 385 44T229 -22Q148 -22 99 32T50 154Q50 178 61 192T84 210T107 214Q132 214 148 197T164 157Z"></path></g><g data-mml-node="msup" transform="translate(500,0)"><g data-mml-node="mi"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="mn" transform="translate(462,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g></g></g></svg></mjx-container>. </p>
<p>This leaves us with two pairs of numbers — <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="16.655ex" height="2.262ex" role="img" focusable="false" viewBox="0 -750 7361.6 1000"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mo"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(389,0)"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 328Z"></path></g><g data-mml-node="mo" transform="translate(1140.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mn" transform="translate(2140.4,0)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="mi" transform="translate(2640.4,0)"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="mo" transform="translate(3069.4,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="mo" transform="translate(3458.4,0)"><path data-c="2C" d="M78 35T78 60T94 103T137 121Q165 121 187 96T210 8Q210 -27 201 -60T180 -117T154 -158T130 -185T117 -194Q113 -194 104 -185T95 -172Q95 -168 106 -156T131 -126T157 -76T173 -3V9L172 8Q170 7 167 6T161 3T152 1T140 0Q113 0 96 17Z"></path></g><g data-mml-node="mo" transform="translate(3903.1,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mn" transform="translate(4292.1,0)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="mi" transform="translate(4792.1,0)"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 328Z"></path></g><g data-mml-node="mo" transform="translate(5543.3,0)"><path data-c="2212" d="M84 237T84 250T98 270H679Q694 262 694 250T679 230H98Q84 237 84 250Z"></path></g><g data-mml-node="mi" transform="translate(6543.6,0)"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="mo" transform="translate(6972.6,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g></g></g></svg></mjx-container> and <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="16.655ex" height="2.262ex" role="img" focusable="false" viewBox="0 -750 7361.6 1000"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mo"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mn" transform="translate(389,0)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="mi" transform="translate(889,0)"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 328Z"></path></g><g data-mml-node="mo" transform="translate(1640.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(2640.4,0)"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="mo" transform="translate(3069.4,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="mo" transform="translate(3458.4,0)"><path data-c="2C" d="M78 35T78 60T94 103T137 121Q165 121 187 96T210 8Q210 -27 201 -60T180 -117T154 -158T130 -185T117 -194Q113 -194 104 -185T95 -172Q95 -168 106 -156T131 -126T157 -76T173 -3V9L172 8Q170 7 167 6T161 3T152 1T140 0Q113 0 96 17Z"></path></g><g data-mml-node="mo" transform="translate(3903.1,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(4292.1,0)"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 328Z"></path></g><g data-mml-node="mo" transform="translate(5043.3,0)"><path data-c="2212" d="M84 237T84 250T98 270H679Q694 262 694 250T679 230H98Q84 237 84 250Z"></path></g><g data-mml-node="mn" transform="translate(6043.6,0)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="mi" transform="translate(6543.6,0)"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="mo" transform="translate(6972.6,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g></g></g></svg></mjx-container>. Let’s square and sum both of these numbers one-by-one. </p>
<p><mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="70.089ex" height="2.452ex" role="img" focusable="false" viewBox="0 -833.9 30979.5 1083.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mo"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(389,0)"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 328Z"></path></g><g data-mml-node="mo" transform="translate(1140.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mn" transform="translate(2140.4,0)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="mi" transform="translate(2640.4,0)"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="msup" transform="translate(3069.4,0)"><g data-mml-node="mo"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g 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720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mn" transform="translate(5506.4,0)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="mi" transform="translate(6006.4,0)"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 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transform="translate(9290.2,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mo" transform="translate(10346,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="msup" transform="translate(10735,0)"><g data-mml-node="mi"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 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-68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mn" transform="translate(12923,0)"><path data-c="34" d="M462 0Q444 3 333 3Q217 3 199 0H190V46H221Q241 46 248 46T265 48T279 53T286 61Q287 63 287 115V165H28V211L179 442Q332 674 334 675Q336 677 355 677H373L379 671V211H471V165H379V114Q379 73 379 66T385 54Q393 47 442 46H471V0H462ZM293 211V545L74 212L183 211H293Z"></path></g><g data-mml-node="mi" transform="translate(13423,0)"><path data-c="1D44E" d="M33 157Q33 258 109 349T280 441Q331 441 370 392Q386 422 416 422Q429 422 439 414T449 394Q449 381 412 234T374 68Q374 43 381 35T402 26Q411 27 422 35Q443 55 463 131Q469 151 473 152Q475 153 483 153H487Q506 153 506 144Q506 138 501 117T481 63T449 13Q436 0 417 -8Q409 -10 393 -10Q359 -10 336 5T306 36L300 51Q299 52 296 50Q294 48 292 46Q233 -10 172 -10Q117 -10 75 30T33 157ZM351 328Q351 334 346 350T323 385T277 405Q242 405 210 374T160 293Q131 214 119 129Q119 126 119 118T118 106Q118 61 136 44T179 26Q217 26 254 59T298 110Q300 114 325 217T351 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<p>What integers would we need for <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.439ex;" xmlns="http://www.w3.org/2000/svg" width="17.754ex" height="2.326ex" role="img" focusable="false" viewBox="0 -833.9 7847.1 1027.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="31" d="M213 578L200 573Q186 568 160 563T102 556H83V602H102Q149 604 189 617T245 641T273 663Q275 666 285 666Q294 666 302 660V361L303 61Q310 54 315 52T339 48T401 46H427V0H416Q395 3 257 3Q121 3 100 0H88V46H114Q136 46 152 46T177 47T193 50T201 52T207 57T213 61V578Z"></path><path data-c="30" d="M96 585Q152 666 249 666Q297 666 345 640T423 548Q460 465 460 320Q460 165 417 83Q397 41 362 16T301 -15T250 -22Q224 -22 198 -16T137 16T82 83Q39 165 39 320Q39 494 96 585ZM321 597Q291 629 250 629Q208 629 178 597Q153 571 145 525T137 333Q137 175 145 125T181 46Q209 16 250 16Q290 16 318 46Q347 76 354 130T362 333Q362 478 354 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<article id="post-Setting-up-a-data-catalog-with-DataHub" class="article article-type-post" itemscope itemprop="blogPost">
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<a class="article-title" href="/2024/07/06/Setting-up-a-data-catalog-with-DataHub/">Setting up a data catalog with DataHub</a>
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<p>In a previous post we’d seen how to <a href="/2024/06/20/Creating-a-realtime-data-platform-with-Pinot-Airflow-Trino-and-Debezium/">create a realtime data platform with Pinot, Trino, Airflow, and Debezium.</a> In this post we’ll see how to setup a data catalog using <a target="_blank" rel="noopener" href="https://datahubproject.io/">DataHub</a>. A data catalog, as the name suggests, is an inventory of the data within the organization. Data catalogs make it easy to find the data within the organisation like tables, data sets, reports, etc.</p>
<h2 id="Before-we-begin"><a href="#Before-we-begin" class="headerlink" title="Before we begin"></a>Before we begin</h2><p>My setup consists of Docker containers required to run DataHub. While DataHub provides features like data lineage, column assertions, and much more, we will look at three of the simpler featuers. One, we’ll look at creating a glossary of the terms that will be used frequently in the organization. Two, we’ll catalog the datasets and views that we saw in the previous post. Three, we’ll create an inventory of dashboards and reports created for various departments within the organisation. </p>
<p>The rationale for this as follows. Imagine a day in the life of a business analyst. Their responsibilities include creating reports and dashboards for various departments. For example, the marketing team may want to see an “orders by day” dashboard so that they can correlate the effects of advertising campaigns with an uptick in the volume of orders. Similarly, the product team may want a report of which features are being used by the users. The requests of both of these teams will be served by the business analyts using the data that’s been brought into the data platform. While they create these reports and dashboards, it’s common for them to receive queries asking where a team member can find a certain report or how to interpret a data point within a report. They may also have to search for tables and data sets to create new reports, acquaint themselves with the vocabulary of the various departments, and so on. </p>
<p>A data catalog makes all of this a more efficient process. In the following sections we’ll see how we can use DataHub to do it. For example, we’ll create the definition of the term “order”, create a list of reports created for the marketing department, and bring in the views and data sets so that they become searchable. </p>
<p>The work of data scientists is similar, too, because they create data sets that can be reused across various models. For example, data sets representing features for various customers can be stored in the platform, made searchable, and used with various models. They, too, benefit from having a data catalog. </p>
<p>Finally, it helps bring people up to speed with the data that is consumed by their department or team. For example, when someone joins the marketing team, pointing them to the data catalog helps them get productive quickly by finding the relevant reports, terminology, etc.</p>
<h2 id="Ingesting-data-sets-and-views"><a href="#Ingesting-data-sets-and-views" class="headerlink" title="Ingesting data sets and views"></a>Ingesting data sets and views</h2><p>To ingest the tables and views, we’ll create a data pipeline which ingets metadata from AWS Glue and writes it to the metadata service. This is done by creating a YAML configuration in DataHub that specifies where to ingest the metadata from, and where to write it. Once this is created, we can schedule it to run periodically so that it stays updated with Glue. </p>
<img src="/2024/07/06/Setting-up-a-data-catalog-with-DataHub/DataSource.png" class="">
<p>The image above shows how we define a “source” and how we ingest it into a “sink”. Here we’ve specified that we’d like to read from Glue and write it to DataHub’s metadata service.</p>
<img src="/2024/07/06/Setting-up-a-data-catalog-with-DataHub/DataSource2.png" class="">
<p>Once the source and destination are defined, we can set a schedule to run the ingestion. This will bring in the metadata about the data sets and views we’ve created in Glue. </p>
<img src="/2024/07/06/Setting-up-a-data-catalog-with-DataHub/DataSource3.png" class="">
<p>The image above shows that a successful run of the ingestion pipeline brings in the views and data sets. These are then browsable in the UI. Similarly, they are also searchable as shown in the following image.</p>
<img src="/2024/07/06/Setting-up-a-data-catalog-with-DataHub/DataSource4.png" class="">
<p>This makes it possible for the analysts and the data scientists to quickly locate data sets. </p>
<h2 id="Defining-the-vocabulary"><a href="#Defining-the-vocabulary" class="headerlink" title="Defining the vocabulary"></a>Defining the vocabulary</h2><p>Next, we’ll create the definition of the word “order”. This can be done from the UI as shown below. The definition can be added by editing the documentation.</p>
<img src="/2024/07/06/Setting-up-a-data-catalog-with-DataHub/Glossary1.png" class="">
<p>Once created, this is available under “Glossary” and in search results. </p>
<img src="/2024/07/06/Setting-up-a-data-catalog-with-DataHub/Glossary2.png" class="">
<h2 id="Data-products"><a href="#Data-products" class="headerlink" title="Data products"></a>Data products</h2><p>Finally, we’ll create a data product. This is the catalog of reports and dashboards created for various departments. For example, the image below shows a dashboard created for the marketing team. </p>
<img src="/2024/07/06/Setting-up-a-data-catalog-with-DataHub/Product1.png" class="">
<p>Expanding the dashboard allows us to look at the documentation for the report. This could contain the definition of the terms used in the report, as shown on the bottom right, a link to the dashboard in Superset, definitions of data points, report owners, and so on. </p>
<img src="/2024/07/06/Setting-up-a-data-catalog-with-DataHub/Product2.png" class="">
<p>That’s it. That’s how a data catalog helps streamline working with data.</p>
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<article id="post-Programming-Puzzles-2" class="article article-type-post" itemscope itemprop="blogPost">
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<a href="/2024/07/03/Programming-Puzzles-2/" class="article-date">
<time datetime="2024-07-03T11:56:27.000Z" itemprop="datePublished">2024-07-03</time>
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<a class="article-title" href="/2024/07/03/Programming-Puzzles-2/">Programming Puzzles 2</a>
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<p>As I continue working my way through the book on programming puzzles, I came across those involving permutations. In this post I’ll collect puzzles with the same theme, both from the book and from the internet. </p>
<h2 id="All-permutations"><a href="#All-permutations" class="headerlink" title="All permutations"></a>All permutations</h2><p>The first puzzle is to compute all the permutations of a given array. By extension, it can be used to compute all the permutations of a string, too, if we view it as an array of characters. To do this we’ll implement <a target="_blank" rel="noopener" href="https://en.wikipedia.org/wiki/Heap%27s_algorithm">Heap’s algorithm</a>. The following is its recursive version. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">heap</span>(<span class="params">permutations: <span class="built_in">list</span>[<span class="built_in">list</span>], A: <span class="built_in">list</span>, n: <span class="built_in">int</span></span>):</span><br><span class="line"> <span class="keyword">if</span> n == <span class="number">1</span>:</span><br><span class="line"> permutations.append(<span class="built_in">list</span>(A))</span><br><span class="line"> <span class="keyword">else</span>:</span><br><span class="line"> heap(permutations, A, n - <span class="number">1</span>)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">for</span> i <span class="keyword">in</span> <span class="built_in">range</span>(n - <span class="number">1</span>):</span><br><span class="line"> <span class="keyword">if</span> n % <span class="number">2</span> == <span class="number">0</span>:</span><br><span class="line"> A[i], A[n - <span class="number">1</span>] = A[n - <span class="number">1</span>], A[i]</span><br><span class="line"> <span class="keyword">else</span>:</span><br><span class="line"> A[<span class="number">0</span>], A[n - <span class="number">1</span>] = A[n - <span class="number">1</span>], A[<span class="number">0</span>]</span><br><span class="line"></span><br><span class="line"> heap(permutations, A, n - <span class="number">1</span>)</span><br></pre></td></tr></table></figure>
<p>The array <code>permutations</code> is the accumulator which will store all the permutations of the array. The initial arguments to the function would be an empty acuumulator, the list to permute, and the length of the list.</p>
<h2 id="Next-permutation"><a href="#Next-permutation" class="headerlink" title="Next permutation"></a>Next permutation</h2><p>The next puzzle we’ll look at is computing the next permutation of the array in lexicographical order. The following implementation has been taken from the book. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">next_permutation</span>(<span class="params">perm: <span class="built_in">list</span>[<span class="built_in">int</span>]</span>) -> <span class="built_in">list</span>[<span class="built_in">int</span>]:</span><br><span class="line"> inversion_point = <span class="built_in">len</span>(perm) - <span class="number">2</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">while</span> (inversion_point >= <span class="number">0</span>) <span class="keyword">and</span> (perm[inversion_point] >= perm[inversion_point + <span class="number">1</span>]):</span><br><span class="line"> inversion_point = inversion_point - <span class="number">1</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">if</span> inversion_point == -<span class="number">1</span>:</span><br><span class="line"> <span class="keyword">return</span> []</span><br><span class="line"></span><br><span class="line"> <span class="keyword">for</span> i <span class="keyword">in</span> <span class="built_in">reversed</span>(<span class="built_in">range</span>(inversion_point + <span class="number">1</span>, <span class="built_in">len</span>(perm))):</span><br><span class="line"> <span class="keyword">if</span> perm[i] > perm[inversion_point]:</span><br><span class="line"> perm[inversion_point], perm[i] = perm[i], perm[inversion_point]</span><br><span class="line"> <span class="keyword">break</span></span><br><span class="line"></span><br><span class="line"> perm[inversion_point + <span class="number">1</span>:] = <span class="built_in">reversed</span>(perm[inversion_point + <span class="number">1</span>:])</span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> perm</span><br></pre></td></tr></table></figure>
<h2 id="Previous-permutation"><a href="#Previous-permutation" class="headerlink" title="Previous permutation"></a>Previous permutation</h2><p>A variation of the puzzle is to compute the previous permutation of the array in lexicographical order. The idea is to “reverse” the logic for computing the next permutation. If we look closely, we’ll find that all we’re changing are the comparison operators.</p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">previous_permutation</span>(<span class="params">perm: <span class="built_in">list</span>[<span class="built_in">int</span>]</span>) -> <span class="built_in">list</span>[<span class="built_in">int</span>]:</span><br><span class="line"> inversion_point = <span class="built_in">len</span>(perm) - <span class="number">2</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">while</span> (inversion_point >= <span class="number">0</span>) <span class="keyword">and</span> (perm[inversion_point] <= perm[inversion_point + <span class="number">1</span>]):</span><br><span class="line"> inversion_point = inversion_point - <span class="number">1</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">if</span> inversion_point == -<span class="number">1</span>:</span><br><span class="line"> <span class="keyword">return</span> []</span><br><span class="line"></span><br><span class="line"> <span class="keyword">for</span> i <span class="keyword">in</span> <span class="built_in">reversed</span>(<span class="built_in">range</span>(inversion_point + <span class="number">1</span>, <span class="built_in">len</span>(perm))):</span><br><span class="line"> <span class="keyword">if</span> perm[i] < perm[inversion_point]:</span><br><span class="line"> perm[inversion_point], perm[i] = perm[i], perm[inversion_point]</span><br><span class="line"> <span class="keyword">break</span></span><br><span class="line"></span><br><span class="line"> perm[inversion_point + <span class="number">1</span>:] = <span class="built_in">reversed</span>(perm[inversion_point + <span class="number">1</span>:])</span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> perm</span><br></pre></td></tr></table></figure>
<h2 id="kth-smallest-permutation"><a href="#kth-smallest-permutation" class="headerlink" title="kth smallest permutation"></a>kth smallest permutation</h2><p>The final puzzle we’ll look at is the one where we need to compute the k’th smallest permutation. The solution to this uses the <code>previous_permutation</code> function that we saw above. The idea is to call this function k times on the lexicographically-largest array. Sorting the array in decreasing order results is the largest. This becomes the input to the <code>previous_permutation</code> function.</p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">kth_smallest_permutation</span>(<span class="params">perm: <span class="built_in">list</span>[<span class="built_in">int</span>], k: <span class="built_in">int</span></span>) -> <span class="built_in">list</span>[<span class="built_in">int</span>]:</span><br><span class="line"> <span class="comment"># -- Arrange the numbers in decreasing order</span></span><br><span class="line"> <span class="comment"># -- thereby creating the lexicographically largest permutation</span></span><br><span class="line"> perm = <span class="built_in">sorted</span>(perm, reverse=<span class="literal">True</span>)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">for</span> _ <span class="keyword">in</span> <span class="built_in">range</span>(k):</span><br><span class="line"> perm = previous_permutation(perm)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> perm</span><br></pre></td></tr></table></figure>
<p>That’s it. These are puzzles involving permutations.</p>
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<article id="post-Programming-Puzzles-1" class="article article-type-post" itemscope itemprop="blogPost">
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<a class="article-title" href="/2024/06/24/Programming-Puzzles-1/">Programming Puzzles 1</a>
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<p>I am working my way through a classic book of programming puzzles. As I work through more of these puzzles, I’ll share what I discover to solidify my understanding and help others who are doing the same. If you’ve ever completed puzzles on a site like <a target="_blank" rel="noopener" href="https://leetcode.com/">leetcode</a>, you’ll notice that the sheer volume of puzzles is overwhelming. However, there are patterns to these puzzles, and becoming familiar with them makes it easier to solve them. In this post we’ll take a look at one such pattern - two pointers - and see how it can be used to solve puzzles involving arrays. </p>
<h2 id="Two-Pointers"><a href="#Two-Pointers" class="headerlink" title="Two Pointers"></a>Two Pointers</h2><p>The idea behind two pointers is that there are, as the name suggests, two pointers that traverse the array, with one pointer leading the other. Using these two pointers we update the array and solve the puzzle at hand. As an illustrative example, let us consider the puzzle where we’re given an array of even and odd numbers and we’d like to move all the even numbers to the front of the array. </p>
<h3 id="Even-and-Odd"><a href="#Even-and-Odd" class="headerlink" title="Even and Odd"></a>Even and Odd</h3><figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">even_odd</span>(<span class="params">A: <span class="built_in">list</span>[<span class="built_in">int</span>]</span>) -> <span class="literal">None</span>:</span><br><span class="line"> <span class="string">"""Move even numbers to the front of the array."""</span></span><br><span class="line"> write_idx = <span class="number">0</span></span><br><span class="line"> idx = <span class="number">0</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">while</span> idx < <span class="built_in">len</span>(A):</span><br><span class="line"> <span class="keyword">if</span> A[idx] % <span class="number">2</span> == <span class="number">0</span>:</span><br><span class="line"> A[write_idx], A[idx] = A[idx], A[write_idx]</span><br><span class="line"> write_idx = write_idx + <span class="number">1</span></span><br><span class="line"></span><br><span class="line"> idx = idx + <span class="number">1</span></span><br></pre></td></tr></table></figure>
<p>The two pointers here are <code>idx</code> and <code>write_idx</code>. While <code>idx</code> traverses the array and indicates the current element, <code>write_idx</code> indicates the position where the next even number should be written. Whenever <code>idx</code> points to an even number, it is written at the position indicated by <code>write_idx</code>. With this logic, if all the numbers in the array are even, <code>idx</code> and <code>write_idx</code> point to the same element i.e. the number is swapped with itself and the pointers are moved forward. </p>
<p>We’ll build upon this technique to remove duplicates from the array. </p>
<h3 id="Remove-Duplicates"><a href="#Remove-Duplicates" class="headerlink" title="Remove Duplicates"></a>Remove Duplicates</h3><p>Consider a sorted array containing duplicate numbers. We’d like to keep only one occurrence of each number and overwrite the rest. This can be solved using two pointers as follows. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">remove_duplicates</span>(<span class="params">A: <span class="built_in">list</span>[<span class="built_in">int</span>]</span>) -> <span class="built_in">int</span>:</span><br><span class="line"> <span class="string">"""Remove all duplicates in the array."""</span></span><br><span class="line"> write_idx, idx = <span class="number">1</span>, <span class="number">1</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">while</span> idx < <span class="built_in">len</span>(A):</span><br><span class="line"> <span class="keyword">if</span> A[write_idx - <span class="number">1</span>] != A[idx]:</span><br><span class="line"> A[write_idx] = A[idx]</span><br><span class="line"> write_idx = write_idx + <span class="number">1</span></span><br><span class="line"></span><br><span class="line"> idx = idx + <span class="number">1</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> write_idx</span><br></pre></td></tr></table></figure>
<p>In this solution, <code>idx</code> and <code>write_idx</code> start at index 1 instead of 0. The reason is that we’d like to look at the number to the left of <code>write_idx</code>, and starting at index 1 allows us to do that. Notice also how we’re writing the <code>if</code> condition to check for duplicity in the vicinity of <code>write_idx</code>; the number to the left of <code>write_idx</code> should be different from the one that <code>idx</code> is presently pointing to. </p>
<p>As a varitation, move the duplicates to the end of the array instead of overwriting them.</p>
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Move Duplicates to the End
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<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">remove_duplicates</span>(<span class="params">A: <span class="built_in">list</span>[<span class="built_in">int</span>]</span>) -> <span class="literal">None</span>:</span><br><span class="line"> <span class="string">"""Remove all duplicates in the array and move them to the end"""</span></span><br><span class="line"> write_idx, idx = <span class="number">1</span>, <span class="number">1</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">while</span> idx < <span class="built_in">len</span>(A):</span><br><span class="line"> <span class="keyword">if</span> A[write_idx - <span class="number">1</span>] != A[idx]:</span><br><span class="line"> A[write_idx], A[idx] = A[idx], A[write_idx]</span><br><span class="line"> write_idx = write_idx + <span class="number">1</span></span><br><span class="line"></span><br><span class="line"> idx = idx + <span class="number">1</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> write_idx</span><br></pre></td></tr></table></figure>
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<p>As another variation, remove a given number from the array by moving it to the end.</p>
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Remove Key from Array
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<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">remove</span>(<span class="params">A: <span class="built_in">list</span>[<span class="built_in">int</span>], k: <span class="built_in">int</span></span>) -> <span class="literal">None</span>:</span><br><span class="line"> write_idx = <span class="number">0</span></span><br><span class="line"> idx = <span class="number">0</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">while</span> idx < <span class="built_in">len</span>(A):</span><br><span class="line"> <span class="keyword">if</span> A[idx] != k:</span><br><span class="line"> A[write_idx], A[idx] = A[idx], A[write_idx]</span><br><span class="line"> write_idx = write_idx + <span class="number">1</span></span><br><span class="line"></span><br><span class="line"> idx = idx + <span class="number">1</span></span><br></pre></td></tr></table></figure>
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<p>With this same pattern, we can now change the puzzle to state that we want at most two instances of the number in the sorted array. </p>
<h3 id="Remove-Duplicates-Variation"><a href="#Remove-Duplicates-Variation" class="headerlink" title="Remove Duplicates Variation"></a>Remove Duplicates Variation</h3><figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">remove_duplicates</span>(<span class="params">A: <span class="built_in">list</span>[<span class="built_in">int</span>]</span>) -> <span class="built_in">int</span>:</span><br><span class="line"> <span class="string">"""Keep at most two instances of the number."""</span></span><br><span class="line"> write_idx = <span class="number">2</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">for</span> idx <span class="keyword">in</span> <span class="built_in">range</span>(<span class="number">2</span>, <span class="built_in">len</span>(A)):</span><br><span class="line"> <span class="keyword">if</span> A[write_idx - <span class="number">2</span>] != A[idx]:</span><br><span class="line"> A[write_idx] = A[idx]</span><br><span class="line"> write_idx = write_idx + <span class="number">1</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> write_idx</span><br></pre></td></tr></table></figure>
<p>Akin to the previous puzzle, we look for duplicates in the vicinity of <code>write_idx</code>. While in the previous puzzle the <code>if</code> condition checked for one number to the left, in this variation we look at two positions to the left of <code>write_idx</code> to keep at most two instances. The remainder of the logic is the same. As a variation, try keeping at most three instances of the number in the sorted array. </p>
<p>Finally, we’ll use the same pattern to solve the <a target="_blank" rel="noopener" href="https://en.wikipedia.org/wiki/Dutch_national_flag_problem">Dutch national flag</a> problem. </p>
<h3 id="Dutch-National-Flag"><a href="#Dutch-National-Flag" class="headerlink" title="Dutch National Flag"></a>Dutch National Flag</h3><p>In this problem, we sort the array by dividing it into three distinct regions. The first region contains elements less than the pivot, the second region contains elements equal to the pivot, and the third region contains elements greater than the pivot. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">dutch_national_flag</span>(<span class="params">A: <span class="built_in">list</span>[<span class="built_in">int</span>], pivot_idx: <span class="built_in">int</span></span>) -> <span class="literal">None</span>:</span><br><span class="line"> <span class="string">"""Divide the array into three distinct regions."""</span></span><br><span class="line"> pivot = A[pivot_idx]</span><br><span class="line"> write_idx = <span class="number">0</span></span><br><span class="line"> idx = <span class="number">0</span></span><br><span class="line"></span><br><span class="line"> <span class="comment"># --- Move all elements less than pivot to the front</span></span><br><span class="line"> <span class="keyword">while</span> idx < <span class="built_in">len</span>(A):</span><br><span class="line"> <span class="keyword">if</span> A[idx] < pivot:</span><br><span class="line"> A[write_idx], A[idx] = A[idx], A[write_idx]</span><br><span class="line"> write_idx = write_idx + <span class="number">1</span></span><br><span class="line"> idx = idx + <span class="number">1</span></span><br><span class="line"></span><br><span class="line"> idx = write_idx</span><br><span class="line"></span><br><span class="line"> <span class="comment"># -- Move all elements equal to the pivot to the middle</span></span><br><span class="line"> <span class="keyword">while</span> idx < <span class="built_in">len</span>(A):</span><br><span class="line"> <span class="keyword">if</span> A[idx] == pivot:</span><br><span class="line"> A[write_idx], A[idx] = A[idx], A[write_idx]</span><br><span class="line"> write_idx = write_idx + <span class="number">1</span></span><br><span class="line"> idx = idx + <span class="number">1</span></span><br><span class="line"></span><br><span class="line"> <span class="comment"># -- All elements greater than pivot have been moved to the end.</span></span><br></pre></td></tr></table></figure>
<p>This problem combines everything we’ve seen so far about two pointers and divides the array into three distinct regions. As we compute the first two regions, the third region is computed as a side-effect. </p>
<p>We can now solve a variation of the Dutch national flag partitioning problem by accepting a list of pivot elements. In this variation all the numbers within the list of pivots appear together i.e. all the elements equal to the first pivot element appear first, equal to second pivot element appear second, and so on. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">dutch_national_flag</span>(<span class="params">A: <span class="built_in">list</span>[<span class="built_in">int</span>], pivots: <span class="built_in">list</span>[<span class="built_in">int</span>]</span>) -> <span class="literal">None</span>:</span><br><span class="line"> <span class="string">"""This is a variation in which all elements with same key appear together."""</span></span><br><span class="line"> write_idx = <span class="number">0</span></span><br><span class="line"></span><br><span class="line"> <span class="keyword">for</span> pivot <span class="keyword">in</span> pivots:</span><br><span class="line"> idx = write_idx</span><br><span class="line"></span><br><span class="line"> <span class="keyword">while</span> idx < <span class="built_in">len</span>(A):</span><br><span class="line"> <span class="keyword">if</span> A[idx] == pivot:</span><br><span class="line"> A[write_idx], A[idx] = A[idx], A[write_idx]</span><br><span class="line"> write_idx = write_idx + <span class="number">1</span></span><br><span class="line"> idx = idx + <span class="number">1</span></span><br></pre></td></tr></table></figure>
<p>That’s it, that’s how we can solve puzzles involving two pointers and arrays.</p>
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<a class="article-title" href="/2024/06/20/Creating-a-realtime-data-platform-with-Pinot-Airflow-Trino-and-Debezium/">Creating a realtime data platform with Pinot, Airflow, Trino, and Debezium</a>
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<p>I’d previously written about creating a <a href="/2023/11/04/Creating-a-data-warehouse-with-Apache-Doris/">realtime data warehouse with Apache Doris and Debezium</a>. In this post we’ll see how to create a realtime data platform with <a target="_blank" rel="noopener" href="https://pinot.apache.org/">Pinot</a>, <a target="_blank" rel="noopener" href="https://trino.io/">Trino</a>, <a target="_blank" rel="noopener" href="https://airflow.apache.org/">Airflow</a>, <a target="_blank" rel="noopener" href="https://debezium.io/">Debezium</a>, and <a target="_blank" rel="noopener" href="https://superset.apache.org/">Superset</a>. In a nutshell, the idea is to bring together data from various sources into Pinot using Debezium, transform it using Airflow, use Trino for query federation, and use Superset to create reports.</p>
<h2 id="Before-We-Begin"><a href="#Before-We-Begin" class="headerlink" title="Before We Begin"></a>Before We Begin</h2><p>My setup consists of Docker containers for running Pinot, Airflow, Debezium, and Trino. Like in the post on creating a warehouse with Doris, we’ll create a <code>person</code> table in Postgres and replicate it into Kafka. We’ll then ingest it into Pinot using its integrated Kafka consumer. Once that’s done, we’ll use Airflow to transform the data to create a view that makes it easier to work with it. Finally, we can use Superset to create reports. The intent of this post is to create a complete data platform that makes it possible to derive insights from data with minimal latency. The overall architecture looks like the following. </p>
<img src="/2024/06/20/Creating-a-realtime-data-platform-with-Pinot-Airflow-Trino-and-Debezium/Container.png" class="">
<h2 id="Getting-Started"><a href="#Getting-Started" class="headerlink" title="Getting Started"></a>Getting Started</h2><p>We’ll begin by creating a schema for the <code>person</code> table in Pinot. This will then be used to create a realtime table. Since we want to use Pinot’s upsert capability to maintain the latest record of each row, we’ll ensure that we define the primary key correctly in the schema. In the case of the <code>person</code> table, it is the combination of the <code>id</code> and the <code>customer_id</code> field. The schema looks as follows. </p>
<figure class="highlight json"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br><span class="line">26</span><br><span class="line">27</span><br><span class="line">28</span><br><span class="line">29</span><br><span class="line">30</span><br><span class="line">31</span><br><span class="line">32</span><br><span class="line">33</span><br></pre></td><td class="code"><pre><span class="line"><span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"schemaName"</span><span class="punctuation">:</span> <span class="string">"person"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"dimensionFieldSpecs"</span><span class="punctuation">:</span> <span class="punctuation">[</span></span><br><span class="line"> <span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"name"</span><span class="punctuation">:</span> <span class="string">"id"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"dataType"</span><span class="punctuation">:</span> <span class="string">"LONG"</span></span><br><span class="line"></span><br><span class="line"> <span class="punctuation">}</span><span class="punctuation">,</span></span><br><span class="line"> <span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"name"</span><span class="punctuation">:</span> <span class="string">"customer_id"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"dataType"</span><span class="punctuation">:</span> <span class="string">"LONG"</span></span><br><span class="line"> <span class="punctuation">}</span><span class="punctuation">,</span></span><br><span class="line"> <span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"name"</span><span class="punctuation">:</span> <span class="string">"source"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"dataType"</span><span class="punctuation">:</span> <span class="string">"JSON"</span></span><br><span class="line"> <span class="punctuation">}</span><span class="punctuation">,</span></span><br><span class="line"> <span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"name"</span><span class="punctuation">:</span> <span class="string">"op"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"dataType"</span><span class="punctuation">:</span> <span class="string">"STRING"</span></span><br><span class="line"> <span class="punctuation">}</span></span><br><span class="line"> <span class="punctuation">]</span> <span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"dateTimeFieldSpecs"</span><span class="punctuation">:</span> <span class="punctuation">[</span><span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"name"</span><span class="punctuation">:</span> <span class="string">"ts_ms"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"dataType"</span><span class="punctuation">:</span> <span class="string">"LONG"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"format"</span> <span class="punctuation">:</span> <span class="string">"1:MILLISECONDS:EPOCH"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"granularity"</span><span class="punctuation">:</span> <span class="string">"1:MILLISECONDS"</span></span><br><span class="line"> <span class="punctuation">}</span><span class="punctuation">]</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"primaryKeyColumns"</span><span class="punctuation">:</span> <span class="punctuation">[</span></span><br><span class="line"> <span class="string">"id"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="string">"customer_id"</span></span><br><span class="line"> <span class="punctuation">]</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"metricFieldSpecs"</span><span class="punctuation">:</span> <span class="punctuation">[</span><span class="punctuation">]</span></span><br><span class="line"><span class="punctuation">}</span></span><br></pre></td></tr></table></figure>
<p>We’ll use the schema to create the realtime table in Pinot. Using <code>ingestionConfig</code> we’ll extract fields out of the Debezium payload and into the columns defined above. This is defined below.</p>
<figure class="highlight json"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br></pre></td><td class="code"><pre><span class="line"><span class="attr">"ingestionConfig"</span><span class="punctuation">:</span><span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"transformConfigs"</span><span class="punctuation">:</span><span class="punctuation">[</span></span><br><span class="line"> <span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"columnName"</span><span class="punctuation">:</span> <span class="string">"id"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"transformFunction"</span><span class="punctuation">:</span> <span class="string">"jsonPath(payload, '$.after.id')"</span></span><br><span class="line"> <span class="punctuation">}</span><span class="punctuation">,</span></span><br><span class="line"> <span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"columnName"</span><span class="punctuation">:</span> <span class="string">"customer_id"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"transformFunction"</span><span class="punctuation">:</span> <span class="string">"jsonPath(payload, '$.after.customer_id')"</span></span><br><span class="line"> <span class="punctuation">}</span><span class="punctuation">,</span></span><br><span class="line"> <span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"columnName"</span><span class="punctuation">:</span> <span class="string">"source"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"transformFunction"</span><span class="punctuation">:</span> <span class="string">"jsonPath(payload, '$.after')"</span></span><br><span class="line"> <span class="punctuation">}</span><span class="punctuation">,</span></span><br><span class="line"> <span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"columnName"</span><span class="punctuation">:</span> <span class="string">"op"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"transformFunction"</span><span class="punctuation">:</span> <span class="string">"jsonPath(payload, '$.op')"</span></span><br><span class="line"> <span class="punctuation">}</span></span><br><span class="line"> <span class="punctuation">]</span></span><br><span class="line"> <span class="punctuation">}</span></span><br></pre></td></tr></table></figure>
<p>Next we’ll create a table in Postgres to store the entries. The SQL query is given below. </p>
<figure class="highlight sql"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">CREATE</span> <span class="keyword">TABLE</span> person (</span><br><span class="line"> id BIGSERIAL <span class="keyword">NOT</span> <span class="keyword">NULL</span>,</span><br><span class="line"> customer_id <span class="type">BIGINT</span> <span class="keyword">NOT</span> <span class="keyword">NULL</span>,</span><br><span class="line"> name TEXT <span class="keyword">NOT</span> <span class="keyword">NULL</span>,</span><br><span class="line"> <span class="keyword">PRIMARY</span> KEY (id, customer_id)</span><br><span class="line">);</span><br></pre></td></tr></table></figure>
<p>Next we’ll create a Debezium source connector to stream change data into Kafka. </p>
<figure class="highlight json"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br><span class="line">19</span><br><span class="line">20</span><br><span class="line">21</span><br><span class="line">22</span><br><span class="line">23</span><br><span class="line">24</span><br><span class="line">25</span><br></pre></td><td class="code"><pre><span class="line"><span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"name"</span><span class="punctuation">:</span> <span class="string">"person"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"config"</span><span class="punctuation">:</span> <span class="punctuation">{</span></span><br><span class="line"> <span class="attr">"connector.class"</span><span class="punctuation">:</span> <span class="string">"io.debezium.connector.postgresql.PostgresConnector"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"database.hostname"</span><span class="punctuation">:</span> <span class="string">"db"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"database.user"</span><span class="punctuation">:</span> <span class="string">"postgres"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"database.password"</span><span class="punctuation">:</span> <span class="string">"my-secret-pw"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"database.dbname"</span><span class="punctuation">:</span> <span class="string">"postgres"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"database.server.name"</span><span class="punctuation">:</span> <span class="string">"postgres"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"table.include.list"</span><span class="punctuation">:</span> <span class="string">".*\\.person"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"plugin.name"</span><span class="punctuation">:</span> <span class="string">"pgoutput"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"publication.autocreate.mode"</span><span class="punctuation">:</span> <span class="string">"filtered"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"time.precision.mode"</span><span class="punctuation">:</span> <span class="string">"connect"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"tombstones.on.delete"</span><span class="punctuation">:</span> <span class="string">"false"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"snapshot.mode"</span><span class="punctuation">:</span> <span class="string">"initial"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"heartbeat.interval.ms"</span><span class="punctuation">:</span> <span class="string">"1000"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"transforms"</span><span class="punctuation">:</span> <span class="string">"route"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"transforms.route.type"</span><span class="punctuation">:</span> <span class="string">"org.apache.kafka.connect.transforms.RegexRouter"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"transforms.route.regex"</span><span class="punctuation">:</span> <span class="string">"([^.]+)\\.([^.]+)\\.([^.]+)"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"transforms.route.replacement"</span><span class="punctuation">:</span> <span class="string">"$3"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"event.processing.failure.handling.mode"</span><span class="punctuation">:</span> <span class="string">"skip"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"producer.override.compression.type"</span><span class="punctuation">:</span> <span class="string">"snappy"</span><span class="punctuation">,</span></span><br><span class="line"> <span class="attr">"topic.prefix"</span><span class="punctuation">:</span> <span class="string">"user_service"</span></span><br><span class="line"> <span class="punctuation">}</span></span><br><span class="line"><span class="punctuation">}</span></span><br></pre></td></tr></table></figure>
<p>Finally, we’ll use <code>curl</code> to send these configs to their appropriate endpoints, beginning with Debezium. </p>
<figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">curl -H <span class="string">"Content-Type: application/json"</span> -XPOST -d @debezium/person.json localhost:8083/connectors | jq .</span><br></pre></td></tr></table></figure>
<p>To create a table in Pinot we’ll first create the schema followed by the table. The <code>curl</code> command is given below. </p>
<figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">curl -F schemaName=@tables/001-person/person_schema.json localhost:9000/schemas | jq .</span><br></pre></td></tr></table></figure>
<p>The command to create the table is given below. </p>
<figure class="highlight bash"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">curl -XPOST -H <span class="string">'Content-Type: application/json'</span> -d @tables/001-person/person_table.json localhost:9000/tables | jq .</span><br></pre></td></tr></table></figure>
<p>With these steps done, the change data from Debezium will be ingested into Pinot. We can view this using Pinot’s query console.</p>
<img src="/2024/06/20/Creating-a-realtime-data-platform-with-Pinot-Airflow-Trino-and-Debezium/Pinot-1.png" class="">
<p>This is where we begin to integrate Airflow and Trino. While the data has been ingested into Pinot, we’ll use Trino for querying. There are two main reasons for this. One, this allows usto federate queries across multiple sources. Two, Pinot’s SQL capabilities are limited. For example, there is no support, as of writing, for creating views. To circumvent these we’ll create a Hive connector in Trino and use it to query Pinot. </p>
<p>The first step is to connect Trino and Pinot. We’ll do this using the Pinot connector. </p>
<figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">CREATE CATALOG pinot USING pinot </span><br><span class="line">WITH (</span><br><span class="line"> "pinot.controller-urls" = 'pinot-controller:9000'</span><br><span class="line">);</span><br></pre></td></tr></table></figure>
<p>Next we’ll create the Hive connector. This will allow us to create views, and more importantly materialized views which act as intermediate datasets or final reports, which can be queried by Superset. I’m using AWS Glue instead of Hive so you’ll have to change the configuration accordingly.</p>
<figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br></pre></td><td class="code"><pre><span class="line">CREATE CATALOG hive USING hive</span><br><span class="line">WITH (</span><br><span class="line"> "hive.metastore" = 'glue',</span><br><span class="line"> "hive.recursive-directories" = 'true',</span><br><span class="line"> "hive.storage-format" = 'PARQUET',</span><br><span class="line"> "hive.insert-existing-partitions-behavior" = 'APPEND',</span><br><span class="line"> "fs.native-s3.enabled" = 'true',</span><br><span class="line"> "s3.endpoint" = 'https://s3.us-east-1.amazonaws.com',</span><br><span class="line"> "s3.region" = 'us-east-1',</span><br><span class="line"> "s3.aws-access-key" = '...',</span><br><span class="line"> "s3.aws-secret-key" = '...'</span><br><span class="line">);</span><br></pre></td></tr></table></figure>
<p>We’ll create a schema to store the views and point it to an S3 bucket.</p>
<figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line">CREATE SCHEMA hive.views</span><br><span class="line">WITH (</span><br><span class="line"> "location" = 's3://your-bucket-name-here/views/'</span><br><span class="line">);</span><br></pre></td></tr></table></figure>
<p>We can then create a view on top of the Pinot table using Hive. </p>
<figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br></pre></td><td class="code"><pre><span class="line">CREATE OR REPLACE VIEW hive.views.person AS</span><br><span class="line">SELECT id,</span><br><span class="line"> customer_id,</span><br><span class="line"> JSON_EXTRACT_SCALAR(source, '$.name') AS name,</span><br><span class="line"> op</span><br><span class="line">FROM pinot.default.person;</span><br></pre></td></tr></table></figure>
<p>Finally, we’ll query the view.</p>
<figure class="highlight plaintext"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line">trino> SELECT * FROM hive.views.person;</span><br><span class="line"> id | customer_id | name | op</span><br><span class="line">----+-------------+-------+----</span><br><span class="line"> 1 | 1 | Fasih | r</span><br><span class="line"> 2 | 2 | Alice | r</span><br><span class="line"> 3 | 3 | Bob | r</span><br><span class="line">(3 rows)</span><br></pre></td></tr></table></figure>
<p>While this helps us ingest and query the data, we’ll take this a step further and use Airflow to create the views instead. This allows us to create views which are time-constrained. For example, if we have an <code>order</code> table which contains all the orders placed by the customers, using Airflow allows to create views which are limited to, say, the last one year by adding a <code>WHERE</code> clause. </p>
<p>We’ll use the <code>TrinoOperator</code> that ships with Airflow and use it to create the view. To do this, we’ll create an <code>sql</code> folder under the <code>dags</code> folder and place our query there. We’ll then create the DAG and operator as follows. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><span class="line">dag = DAG(</span><br><span class="line"> dag_id=<span class="string">"create_views"</span>,</span><br><span class="line"> catchup=<span class="literal">False</span>,</span><br><span class="line"> schedule=<span class="string">"@daily"</span>,</span><br><span class="line"> start_date=pendulum.now(<span class="string">"GMT"</span>)</span><br><span class="line">)</span><br><span class="line"></span><br><span class="line">person = TrinoOperator(</span><br><span class="line"> task_id=<span class="string">"person"</span>,</span><br><span class="line"> trino_conn_id=<span class="string">"trino"</span>,</span><br><span class="line"> sql=<span class="string">"sql/views/person.sql"</span>,</span><br><span class="line"> dag=dag</span><br><span class="line">)</span><br></pre></td></tr></table></figure>
<h2 id="Workflow"><a href="#Workflow" class="headerlink" title="Workflow"></a>Workflow</h2><p>The kind of workflow this setup enables is the one where the data engineering team is responsible for ingesting the data into Pinot and creating the base views on top of it. The business intelligence / analytics engineering, and data science teams can then use Airflow to create datasets that they need. These can be created as materialized views to speed up reporting or training of machine learning models. Another advantage of this setup is that bringing in older data, say, of the last two years instead of one, is a matter of changing the query of the base view. This avoids complicated backfills and speeds things up significantly. </p>
<p>As an aside, it is possible to use <a target="_blank" rel="noopener" href="https://www.getdbt.com/">DBT</a> instead of <code>TrinoOperator</code>. It can be used in conjunction with <code>TrinoOperator</code>, too. However, I preferred using the in-built operator to keep the stack simpler.</p>
<h2 id="Cost"><a href="#Cost" class="headerlink" title="Cost"></a>Cost</h2><p>Before we conclude, we’ll quickly go over how to keep the cost of the Pinot cluster low while using this setup. <a target="_blank" rel="noopener" href="https://docs.pinot.apache.org/operators/operating-pinot/separating-data-storage-by-age">In the official documentation</a> it says that data can be seperated by age; older data can be stored in HDDs while the newer data can be stored in SSDs. This allows lowering the cost of the cluster. </p>
<p>An alternative approach is to keep all the data in HDDs and load subsets into Hive for querying. This also allows changing the date range of the views by simply updating the queries. In essence, Pinot becomes the permanent storage for data while Trino and Hive become the intermediate query and storage layer.</p>
<p>That’s it. That’s how we can create a realtime data platform using Pinot, Trino, Debezium, and Airflow. </p>
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<time datetime="2024-06-17T03:10:07.000Z" itemprop="datePublished">2024-06-17</time>
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<a class="article-title" href="/2024/06/17/A-note-on-exponents/">A note on exponents</a>
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<div class="article-entry" itemprop="articleBody">
<p>In the chapter on exponents the authors mention that if a base is raised to both a power and a root, we should calculate the root first and then the power. This works perfectly well. However, reversing the order produces correct results, too. In this post we’ll see why that works using the properties of exponents.</p>
<p>Let’s say we have a base <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="0.971ex" height="1.595ex" role="img" focusable="false" viewBox="0 -694 429 705"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g></g></g></svg></mjx-container> that is raised to power <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.439ex;" xmlns="http://www.w3.org/2000/svg" width="1.138ex" height="1.439ex" role="img" focusable="false" viewBox="0 -442 503 636"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D45D" d="M23 287Q24 290 25 295T30 317T40 348T55 381T75 411T101 433T134 442Q209 442 230 378L240 387Q302 442 358 442Q423 442 460 395T497 281Q497 173 421 82T249 -10Q227 -10 210 -4Q199 1 187 11T168 28L161 36Q160 35 139 -51T118 -138Q118 -144 126 -145T163 -148H188Q194 -155 194 -157T191 -175Q188 -187 185 -190T172 -194Q170 -194 161 -194T127 -193T65 -192Q-5 -192 -24 -194H-32Q-39 -187 -39 -183Q-37 -156 -26 -148H-6Q28 -147 33 -136Q36 -130 94 103T155 350Q156 355 156 364Q156 405 131 405Q109 405 94 377T71 316T59 280Q57 278 43 278H29Q23 284 23 287ZM178 102Q200 26 252 26Q282 26 310 49T356 107Q374 141 392 215T411 325V331Q411 405 350 405Q339 405 328 402T306 393T286 380T269 365T254 350T243 336T235 326L232 322Q232 321 229 308T218 264T204 212Q178 106 178 102Z"></path></g></g></g></svg></mjx-container> and root <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.02ex" height="1.025ex" role="img" focusable="false" viewBox="0 -442 451 453"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D45F" d="M21 287Q22 290 23 295T28 317T38 348T53 381T73 411T99 433T132 442Q161 442 183 430T214 408T225 388Q227 382 228 382T236 389Q284 441 347 441H350Q398 441 422 400Q430 381 430 363Q430 333 417 315T391 292T366 288Q346 288 334 299T322 328Q322 376 378 392Q356 405 342 405Q286 405 239 331Q229 315 224 298T190 165Q156 25 151 16Q138 -11 108 -11Q95 -11 87 -5T76 7T74 17Q74 30 114 189T154 366Q154 405 128 405Q107 405 92 377T68 316T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g></g></g></svg></mjx-container>. We could write this as <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="2.431ex" height="2.11ex" role="img" focusable="false" viewBox="0 -921.4 1074.6 932.4"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="msup"><g data-mml-node="mi"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="TeXAtom" transform="translate(462,363) scale(0.707)" data-mjx-texclass="ORD"><g data-mml-node="mfrac"><g data-mml-node="mi" transform="translate(220,477.2) scale(0.707)"><path data-c="1D45D" d="M23 287Q24 290 25 295T30 317T40 348T55 381T75 411T101 433T134 442Q209 442 230 378L240 387Q302 442 358 442Q423 442 460 395T497 281Q497 173 421 82T249 -10Q227 -10 210 -4Q199 1 187 11T168 28L161 36Q160 35 139 -51T118 -138Q118 -144 126 -145T163 -148H188Q194 -155 194 -157T191 -175Q188 -187 185 -190T172 -194Q170 -194 161 -194T127 -193T65 -192Q-5 -192 -24 -194H-32Q-39 -187 -39 -183Q-37 -156 -26 -148H-6Q28 -147 33 -136Q36 -130 94 103T155 350Q156 355 156 364Q156 405 131 405Q109 405 94 377T71 316T59 280Q57 278 43 278H29Q23 284 23 287ZM178 102Q200 26 252 26Q282 26 310 49T356 107Q374 141 392 215T411 325V331Q411 405 350 405Q339 405 328 402T306 393T286 380T269 365T254 350T243 336T235 326L232 322Q232 321 229 308T218 264T204 212Q178 106 178 102Z"></path></g><g data-mml-node="mi" transform="translate(238.4,-345) scale(0.707)"><path data-c="1D45F" d="M21 287Q22 290 23 295T28 317T38 348T53 381T73 411T99 433T132 442Q161 442 183 430T214 408T225 388Q227 382 228 382T236 389Q284 441 347 441H350Q398 441 422 400Q430 381 430 363Q430 333 417 315T391 292T366 288Q346 288 334 299T322 328Q322 376 378 392Q356 405 342 405Q286 405 239 331Q229 315 224 298T190 165Q156 25 151 16Q138 -11 108 -11Q95 -11 87 -5T76 7T74 17Q74 30 114 189T154 366Q154 405 128 405Q107 405 92 377T68 316T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><rect width="555.7" height="60" x="120" y="220"></rect></g></g></g></g></g></svg></mjx-container>. From the properties of exponents, we could rewrite this as <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="5.181ex" height="2.771ex" role="img" focusable="false" viewBox="0 -974.6 2289.8 1224.6"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mo"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="msup" transform="translate(389,0)"><g data-mml-node="mi"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="TeXAtom" transform="translate(462,363) scale(0.707)" data-mjx-texclass="ORD"><g data-mml-node="mfrac"><g data-mml-node="mn" transform="translate(220,394) scale(0.707)"><path data-c="31" d="M213 578L200 573Q186 568 160 563T102 556H83V602H102Q149 604 189 617T245 641T273 663Q275 666 285 666Q294 666 302 660V361L303 61Q310 54 315 52T339 48T401 46H427V0H416Q395 3 257 3Q121 3 100 0H88V46H114Q136 46 152 46T177 47T193 50T201 52T207 57T213 61V578Z"></path></g><g data-mml-node="mi" transform="translate(237.3,-345) scale(0.707)"><path data-c="1D45F" d="M21 287Q22 290 23 295T28 317T38 348T53 381T73 411T99 433T132 442Q161 442 183 430T214 408T225 388Q227 382 228 382T236 389Q284 441 347 441H350Q398 441 422 400Q430 381 430 363Q430 333 417 315T391 292T366 288Q346 288 334 299T322 328Q322 376 378 392Q356 405 342 405Q286 405 239 331Q229 315 224 298T190 165Q156 25 151 16Q138 -11 108 -11Q95 -11 87 -5T76 7T74 17Q74 30 114 189T154 366Q154 405 128 405Q107 405 92 377T68 316T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><rect width="553.6" height="60" x="120" y="220"></rect></g></g></g><g data-mml-node="msup" transform="translate(1462.1,0)"><g data-mml-node="mo"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="TeXAtom" transform="translate(422,363) scale(0.707)" data-mjx-texclass="ORD"><g data-mml-node="mi"><path data-c="1D45D" d="M23 287Q24 290 25 295T30 317T40 348T55 381T75 411T101 433T134 442Q209 442 230 378L240 387Q302 442 358 442Q423 442 460 395T497 281Q497 173 421 82T249 -10Q227 -10 210 -4Q199 1 187 11T168 28L161 36Q160 35 139 -51T118 -138Q118 -144 126 -145T163 -148H188Q194 -155 194 -157T191 -175Q188 -187 185 -190T172 -194Q170 -194 161 -194T127 -193T65 -192Q-5 -192 -24 -194H-32Q-39 -187 -39 -183Q-37 -156 -26 -148H-6Q28 -147 33 -136Q36 -130 94 103T155 350Q156 355 156 364Q156 405 131 405Q109 405 94 377T71 316T59 280Q57 278 43 278H29Q23 284 23 287ZM178 102Q200 26 252 26Q282 26 310 49T356 107Q374 141 392 215T411 325V331Q411 405 350 405Q339 405 328 402T306 393T286 380T269 365T254 350T243 336T235 326L232 322Q232 321 229 308T218 264T204 212Q178 106 178 102Z"></path></g></g></g></g></g></svg></mjx-container>. Alternatively, it can be written as <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="4.477ex" height="2.23ex" role="img" focusable="false" viewBox="0 -974.6 1978.9 985.6"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="msup"><g data-mml-node="mi"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="TeXAtom" transform="translate(462,363) scale(0.707)" data-mjx-texclass="ORD"><g data-mml-node="mfrac"><g data-mml-node="mn" transform="translate(220,394) scale(0.707)"><path data-c="31" d="M213 578L200 573Q186 568 160 563T102 556H83V602H102Q149 604 189 617T245 641T273 663Q275 666 285 666Q294 666 302 660V361L303 61Q310 54 315 52T339 48T401 46H427V0H416Q395 3 257 3Q121 3 100 0H88V46H114Q136 46 152 46T177 47T193 50T201 52T207 57T213 61V578Z"></path></g><g data-mml-node="mi" transform="translate(237.3,-345) scale(0.707)"><path data-c="1D45F" d="M21 287Q22 290 23 295T28 317T38 348T53 381T73 411T99 433T132 442Q161 442 183 430T214 408T225 388Q227 382 228 382T236 389Q284 441 347 441H350Q398 441 422 400Q430 381 430 363Q430 333 417 315T391 292T366 288Q346 288 334 299T322 328Q322 376 378 392Q356 405 342 405Q286 405 239 331Q229 315 224 298T190 165Q156 25 151 16Q138 -11 108 -11Q95 -11 87 -5T76 7T74 17Q74 30 114 189T154 366Q154 405 128 405Q107 405 92 377T68 316T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><rect width="553.6" height="60" x="120" y="220"></rect></g><g data-mml-node="mo" transform="translate(793.6,0)"><path data-c="D7" d="M630 29Q630 9 609 9Q604 9 587 25T493 118L389 222L284 117Q178 13 175 11Q171 9 168 9Q160 9 154 15T147 29Q147 36 161 51T255 146L359 250L255 354Q174 435 161 449T147 471Q147 480 153 485T168 490Q173 490 175 489Q178 487 284 383L389 278L493 382Q570 459 587 475T609 491Q630 491 630 471Q630 464 620 453T522 355L418 250L522 145Q606 61 618 48T630 29Z"></path></g><g data-mml-node="mi" transform="translate(1571.6,0)"><path data-c="1D45D" d="M23 287Q24 290 25 295T30 317T40 348T55 381T75 411T101 433T134 442Q209 442 230 378L240 387Q302 442 358 442Q423 442 460 395T497 281Q497 173 421 82T249 -10Q227 -10 210 -4Q199 1 187 11T168 28L161 36Q160 35 139 -51T118 -138Q118 -144 126 -145T163 -148H188Q194 -155 194 -157T191 -175Q188 -187 185 -190T172 -194Q170 -194 161 -194T127 -193T65 -192Q-5 -192 -24 -194H-32Q-39 -187 -39 -183Q-37 -156 -26 -148H-6Q28 -147 33 -136Q36 -130 94 103T155 350Q156 355 156 364Q156 405 131 405Q109 405 94 377T71 316T59 280Q57 278 43 278H29Q23 284 23 287ZM178 102Q200 26 252 26Q282 26 310 49T356 107Q374 141 392 215T411 325V331Q411 405 350 405Q339 405 328 402T306 393T286 380T269 365T254 350T243 336T235 326L232 322Q232 321 229 308T218 264T204 212Q178 106 178 102Z"></path></g></g></g></g></g></svg></mjx-container>. Since multiplication is commutative, we can switch the order of operations and rewrite it as <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="5.181ex" height="2.771ex" role="img" focusable="false" viewBox="0 -974.6 2289.8 1224.6"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mo"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="msup" transform="translate(389,0)"><g data-mml-node="mi"><path data-c="1D44F" d="M73 647Q73 657 77 670T89 683Q90 683 161 688T234 694Q246 694 246 685T212 542Q204 508 195 472T180 418L176 399Q176 396 182 402Q231 442 283 442Q345 442 383 396T422 280Q422 169 343 79T173 -11Q123 -11 82 27T40 150V159Q40 180 48 217T97 414Q147 611 147 623T109 637Q104 637 101 637H96Q86 637 83 637T76 640T73 647ZM336 325V331Q336 405 275 405Q258 405 240 397T207 376T181 352T163 330L157 322L136 236Q114 150 114 114Q114 66 138 42Q154 26 178 26Q211 26 245 58Q270 81 285 114T318 219Q336 291 336 325Z"></path></g><g data-mml-node="mi" transform="translate(462,363) scale(0.707)"><path data-c="1D45D" d="M23 287Q24 290 25 295T30 317T40 348T55 381T75 411T101 433T134 442Q209 442 230 378L240 387Q302 442 358 442Q423 442 460 395T497 281Q497 173 421 82T249 -10Q227 -10 210 -4Q199 1 187 11T168 28L161 36Q160 35 139 -51T118 -138Q118 -144 126 -145T163 -148H188Q194 -155 194 -157T191 -175Q188 -187 185 -190T172 -194Q170 -194 161 -194T127 -193T65 -192Q-5 -192 -24 -194H-32Q-39 -187 -39 -183Q-37 -156 -26 -148H-6Q28 -147 33 -136Q36 -130 94 103T155 350Q156 355 156 364Q156 405 131 405Q109 405 94 377T71 316T59 280Q57 278 43 278H29Q23 284 23 287ZM178 102Q200 26 252 26Q282 26 310 49T356 107Q374 141 392 215T411 325V331Q411 405 350 405Q339 405 328 402T306 393T286 380T269 365T254 350T243 336T235 326L232 322Q232 321 229 308T218 264T204 212Q178 106 178 102Z"></path></g></g><g data-mml-node="msup" transform="translate(1256.7,0)"><g data-mml-node="mo"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="TeXAtom" transform="translate(422,363) scale(0.707)" data-mjx-texclass="ORD"><g data-mml-node="mfrac"><g data-mml-node="mn" transform="translate(220,394) scale(0.707)"><path data-c="31" d="M213 578L200 573Q186 568 160 563T102 556H83V602H102Q149 604 189 617T245 641T273 663Q275 666 285 666Q294 666 302 660V361L303 61Q310 54 315 52T339 48T401 46H427V0H416Q395 3 257 3Q121 3 100 0H88V46H114Q136 46 152 46T177 47T193 50T201 52T207 57T213 61V578Z"></path></g><g data-mml-node="mi" transform="translate(237.3,-345) scale(0.707)"><path data-c="1D45F" d="M21 287Q22 290 23 295T28 317T38 348T53 381T73 411T99 433T132 442Q161 442 183 430T214 408T225 388Q227 382 228 382T236 389Q284 441 347 441H350Q398 441 422 400Q430 381 430 363Q430 333 417 315T391 292T366 288Q346 288 334 299T322 328Q322 376 378 392Q356 405 342 405Q286 405 239 331Q229 315 224 298T190 165Q156 25 151 16Q138 -11 108 -11Q95 -11 87 -5T76 7T74 17Q74 30 114 189T154 366Q154 405 128 405Q107 405 92 377T68 316T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><rect width="553.6" height="60" x="120" y="220"></rect></g></g></g></g></g></svg></mjx-container>. This means we can calculate the power first and then take the root. </p>
<p>Let’s take a look at a numerical example. Consider <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: 0;" xmlns="http://www.w3.org/2000/svg" width="2.589ex" height="2.205ex" role="img" focusable="false" viewBox="0 -974.6 1144.1 974.6"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="msup"><g data-mml-node="mn"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="TeXAtom" transform="translate(533,363) scale(0.707)" data-mjx-texclass="ORD"><g data-mml-node="mfrac"><g data-mml-node="mn" transform="translate(220,394) scale(0.707)"><path data-c="36" d="M42 313Q42 476 123 571T303 666Q372 666 402 630T432 550Q432 525 418 510T379 495Q356 495 341 509T326 548Q326 592 373 601Q351 623 311 626Q240 626 194 566Q147 500 147 364L148 360Q153 366 156 373Q197 433 263 433H267Q313 433 348 414Q372 400 396 374T435 317Q456 268 456 210V192Q456 169 451 149Q440 90 387 34T253 -22Q225 -22 199 -14T143 16T92 75T56 172T42 313ZM257 397Q227 397 205 380T171 335T154 278T148 216Q148 133 160 97T198 39Q222 21 251 21Q302 21 329 59Q342 77 347 104T352 209Q352 289 347 316T329 361Q302 397 257 397Z"></path></g><g data-mml-node="mn" transform="translate(220,-345) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><rect width="553.6" height="60" x="120" y="220"></rect></g></g></g></g></g></svg></mjx-container>. We know that the answer should be equal to <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: 0;" xmlns="http://www.w3.org/2000/svg" width="2.119ex" height="1.885ex" role="img" focusable="false" viewBox="0 -833.2 936.6 833.2"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="msup"><g data-mml-node="mn"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><g data-mml-node="mn" transform="translate(533,363) scale(0.707)"><path data-c="33" d="M127 463Q100 463 85 480T69 524Q69 579 117 622T233 665Q268 665 277 664Q351 652 390 611T430 522Q430 470 396 421T302 350L299 348Q299 347 308 345T337 336T375 315Q457 262 457 175Q457 96 395 37T238 -22Q158 -22 100 21T42 130Q42 158 60 175T105 193Q133 193 151 175T169 130Q169 119 166 110T159 94T148 82T136 74T126 70T118 67L114 66Q165 21 238 21Q293 21 321 74Q338 107 338 175V195Q338 290 274 322Q259 328 213 329L171 330L168 332Q166 335 166 348Q166 366 174 366Q202 366 232 371Q266 376 294 413T322 525V533Q322 590 287 612Q265 626 240 626Q208 626 181 615T143 592T132 580H135Q138 579 143 578T153 573T165 566T175 555T183 540T186 520Q186 498 172 481T127 463Z"></path></g></g></g></g></svg></mjx-container>. If we were to calculate the root first, we get <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="9.957ex" height="2.739ex" role="img" focusable="false" viewBox="0 -960.5 4401.1 1210.5"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mo"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="msqrt" transform="translate(389,0)"><g transform="translate(853,0)"><g data-mml-node="mn"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g><g data-mml-node="mo" transform="translate(0,100.5)"><path data-c="221A" d="M95 178Q89 178 81 186T72 200T103 230T169 280T207 309Q209 311 212 311H213Q219 311 227 294T281 177Q300 134 312 108L397 -77Q398 -77 501 136T707 565T814 786Q820 800 834 800Q841 800 846 794T853 782V776L620 293L385 -193Q381 -200 366 -200Q357 -200 354 -197Q352 -195 256 15L160 225L144 214Q129 202 113 190T95 178Z"></path></g><rect width="500" height="60" x="853" y="840.5"></rect></g><g data-mml-node="msup" transform="translate(1742,0)"><g data-mml-node="mo"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="mn" transform="translate(422,363) scale(0.707)"><path data-c="36" d="M42 313Q42 476 123 571T303 666Q372 666 402 630T432 550Q432 525 418 510T379 495Q356 495 341 509T326 548Q326 592 373 601Q351 623 311 626Q240 626 194 566Q147 500 147 364L148 360Q153 366 156 373Q197 433 263 433H267Q313 433 348 414Q372 400 396 374T435 317Q456 268 456 210V192Q456 169 451 149Q440 90 387 34T253 -22Q225 -22 199 -14T143 16T92 75T56 172T42 313ZM257 397Q227 397 205 380T171 335T154 278T148 216Q148 133 160 97T198 39Q222 21 251 21Q302 21 329 59Q342 77 347 104T352 209Q352 289 347 316T329 361Q302 397 257 397Z"></path></g></g><g data-mml-node="mo" transform="translate(2845.3,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mn" transform="translate(3901.1,0)"><path data-c="38" d="M70 417T70 494T124 618T248 666Q319 666 374 624T429 515Q429 485 418 459T392 417T361 389T335 371T324 363L338 354Q352 344 366 334T382 323Q457 264 457 174Q457 95 399 37T249 -22Q159 -22 101 29T43 155Q43 263 172 335L154 348Q133 361 127 368Q70 417 70 494ZM286 386L292 390Q298 394 301 396T311 403T323 413T334 425T345 438T355 454T364 471T369 491T371 513Q371 556 342 586T275 624Q268 625 242 625Q201 625 165 599T128 534Q128 511 141 492T167 463T217 431Q224 426 228 424L286 386ZM250 21Q308 21 350 55T392 137Q392 154 387 169T375 194T353 216T330 234T301 253T274 270Q260 279 244 289T218 306L210 311Q204 311 181 294T133 239T107 157Q107 98 150 60T250 21Z"></path></g></g></g></svg></mjx-container>. If we were to calculate the power first and then take the root, we’d get <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="9.628ex" height="2.771ex" role="img" focusable="false" viewBox="0 -974.6 4255.7 1224.6"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mo"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mn" transform="translate(389,0)"><path data-c="36" d="M42 313Q42 476 123 571T303 666Q372 666 402 630T432 550Q432 525 418 510T379 495Q356 495 341 509T326 548Q326 592 373 601Q351 623 311 626Q240 626 194 566Q147 500 147 364L148 360Q153 366 156 373Q197 433 263 433H267Q313 433 348 414Q372 400 396 374T435 317Q456 268 456 210V192Q456 169 451 149Q440 90 387 34T253 -22Q225 -22 199 -14T143 16T92 75T56 172T42 313ZM257 397Q227 397 205 380T171 335T154 278T148 216Q148 133 160 97T198 39Q222 21 251 21Q302 21 329 59Q342 77 347 104T352 209Q352 289 347 316T329 361Q302 397 257 397Z"></path><path data-c="34" d="M462 0Q444 3 333 3Q217 3 199 0H190V46H221Q241 46 248 46T265 48T279 53T286 61Q287 63 287 115V165H28V211L179 442Q332 674 334 675Q336 677 355 677H373L379 671V211H471V165H379V114Q379 73 379 66T385 54Q393 47 442 46H471V0H462ZM293 211V545L74 212L183 211H293Z" transform="translate(500,0)"></path></g><g data-mml-node="msup" transform="translate(1389,0)"><g data-mml-node="mo"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="mfrac" transform="translate(422,363) scale(0.707)"><g data-mml-node="mn" transform="translate(220,394) scale(0.707)"><path data-c="31" d="M213 578L200 573Q186 568 160 563T102 556H83V602H102Q149 604 189 617T245 641T273 663Q275 666 285 666Q294 666 302 660V361L303 61Q310 54 315 52T339 48T401 46H427V0H416Q395 3 257 3Q121 3 100 0H88V46H114Q136 46 152 46T177 47T193 50T201 52T207 57T213 61V578Z"></path></g><g data-mml-node="mn" transform="translate(220,-345) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g><rect width="553.6" height="60" x="120" y="220"></rect></g></g><g data-mml-node="mo" transform="translate(2699.9,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mn" transform="translate(3755.7,0)"><path data-c="38" d="M70 417T70 494T124 618T248 666Q319 666 374 624T429 515Q429 485 418 459T392 417T361 389T335 371T324 363L338 354Q352 344 366 334T382 323Q457 264 457 174Q457 95 399 37T249 -22Q159 -22 101 29T43 155Q43 263 172 335L154 348Q133 361 127 368Q70 417 70 494ZM286 386L292 390Q298 394 301 396T311 403T323 413T334 425T345 438T355 454T364 471T369 491T371 513Q371 556 342 586T275 624Q268 625 242 625Q201 625 165 599T128 534Q128 511 141 492T167 463T217 431Q224 426 228 424L286 386ZM250 21Q308 21 350 55T392 137Q392 154 387 169T375 194T353 216T330 234T301 253T274 270Q260 279 244 289T218 306L210 311Q204 311 181 294T133 239T107 157Q107 98 150 60T250 21Z"></path></g></g></g></svg></mjx-container>. As we can see, we get the same result. </p>
<p>Therefore, we can apply the operations in any order.</p>
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<article id="post-Factoring-Quadratics" class="article article-type-post" itemscope itemprop="blogPost">
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<time datetime="2024-06-10T06:35:58.000Z" itemprop="datePublished">2024-06-10</time>
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<a class="article-title" href="/2024/06/10/Factoring-Quadratics/">Factoring Quadratics</a>
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<p>While reading through the chapter on solving quadratics of a math textbook, I came across a paragraph where the authors mention that factoring quadratics takes a bit of ingenuity, experience, and dumb luck. I spent some time creating an alternative method from the one mentioned in the book which makes factoring quadratics a matter of following a simple set of steps, and removes the element of luck from it. In this post I will review some of the concepts mentioned in the book, and solve through one of the more difficult problems to illustrate my method.</p>
<h2 id="Concepts"><a href="#Concepts" class="headerlink" title="Concepts"></a>Concepts</h2><p>Let’s begin by looking at the quadratic <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="11.37ex" height="2.072ex" role="img" focusable="false" viewBox="0 -833.9 5025.4 915.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="msup"><g data-mml-node="mi"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mn" transform="translate(605,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g><g data-mml-node="mo" transform="translate(1230.8,0)"><path data-c="2212" d="M84 237T84 250T98 270H679Q694 262 694 250T679 230H98Q84 237 84 250Z"></path></g><g data-mml-node="mn" transform="translate(2231,0)"><path data-c="33" d="M127 463Q100 463 85 480T69 524Q69 579 117 622T233 665Q268 665 277 664Q351 652 390 611T430 522Q430 470 396 421T302 350L299 348Q299 347 308 345T337 336T375 315Q457 262 457 175Q457 96 395 37T238 -22Q158 -22 100 21T42 130Q42 158 60 175T105 193Q133 193 151 175T169 130Q169 119 166 110T159 94T148 82T136 74T126 70T118 67L114 66Q165 21 238 21Q293 21 321 74Q338 107 338 175V195Q338 290 274 322Q259 328 213 329L171 330L168 332Q166 335 166 348Q166 366 174 366Q202 366 232 371Q266 376 294 413T322 525V533Q322 590 287 612Q265 626 240 626Q208 626 181 615T143 592T132 580H135Q138 579 143 578T153 573T165 566T175 555T183 540T186 520Q186 498 172 481T127 463Z"></path></g><g data-mml-node="mi" transform="translate(2731,0)"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mo" transform="translate(3525.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mn" transform="translate(4525.4,0)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g></g></svg></mjx-container>. This can be factored as <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="14.031ex" height="2.262ex" role="img" focusable="false" viewBox="0 -750 6201.9 1000"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mo"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(389,0)"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mo" transform="translate(1183.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(2183.4,0)"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mo" transform="translate(2755.4,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="mo" transform="translate(3144.4,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(3533.4,0)"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mo" transform="translate(4327.7,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(5327.9,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g><g data-mml-node="mo" transform="translate(5812.9,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g></g></g></svg></mjx-container>. Multiplying the terms gives us <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="18.416ex" height="2.452ex" role="img" focusable="false" viewBox="0 -833.9 8139.9 1083.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="msup"><g data-mml-node="mi"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mn" transform="translate(605,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g><g data-mml-node="mo" transform="translate(1230.8,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mo" transform="translate(2231,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(2620,0)"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mo" transform="translate(3414.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(4414.4,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g><g data-mml-node="mo" transform="translate(4899.4,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="mi" transform="translate(5288.4,0)"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mo" transform="translate(6082.7,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(7082.9,0)"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mi" transform="translate(7654.9,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g></g></g></svg></mjx-container>. Comparing this to the coefficients of the the original quadratic gives us <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="11.066ex" height="1.69ex" role="img" focusable="false" viewBox="0 -665 4891 747"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mo" transform="translate(794.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(1794.4,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g><g data-mml-node="mo" transform="translate(2557.2,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mo" transform="translate(3613,0)"><path data-c="2212" d="M84 237T84 250T98 270H679Q694 262 694 250T679 230H98Q84 237 84 250Z"></path></g><g data-mml-node="mn" transform="translate(4391,0)"><path data-c="33" d="M127 463Q100 463 85 480T69 524Q69 579 117 622T233 665Q268 665 277 664Q351 652 390 611T430 522Q430 470 396 421T302 350L299 348Q299 347 308 345T337 336T375 315Q457 262 457 175Q457 96 395 37T238 -22Q158 -22 100 21T42 130Q42 158 60 175T105 193Q133 193 151 175T169 130Q169 119 166 110T159 94T148 82T136 74T126 70T118 67L114 66Q165 21 238 21Q293 21 321 74Q338 107 338 175V195Q338 290 274 322Q259 328 213 329L171 330L168 332Q166 335 166 348Q166 366 174 366Q202 366 232 371Q266 376 294 413T322 525V533Q322 590 287 612Q265 626 240 626Q208 626 181 615T143 592T132 580H135Q138 579 143 578T153 573T165 566T175 555T183 540T186 520Q186 498 172 481T127 463Z"></path></g></g></g></svg></mjx-container>, and <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="6.54ex" height="1.692ex" role="img" focusable="false" viewBox="0 -666 2890.6 748"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mi" transform="translate(572,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g><g data-mml-node="mo" transform="translate(1334.8,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mn" transform="translate(2390.6,0)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g></g></svg></mjx-container>. For a simple quadratic, we can guess that <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="7.203ex" height="1.692ex" role="img" focusable="false" viewBox="0 -666 3183.6 748"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mo" transform="translate(849.8,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mo" transform="translate(1905.6,0)"><path data-c="2212" d="M84 237T84 250T98 270H679Q694 262 694 250T679 230H98Q84 237 84 250Z"></path></g><g data-mml-node="mn" transform="translate(2683.6,0)"><path data-c="31" d="M213 578L200 573Q186 568 160 563T102 556H83V602H102Q149 604 189 617T245 641T273 663Q275 666 285 666Q294 666 302 660V361L303 61Q310 54 315 52T339 48T401 46H427V0H416Q395 3 257 3Q121 3 100 0H88V46H114Q136 46 152 46T177 47T193 50T201 52T207 57T213 61V578Z"></path></g></g></g></svg></mjx-container> and <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="7.006ex" height="1.692ex" role="img" focusable="false" viewBox="0 -666 3096.6 748"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g><g data-mml-node="mo" transform="translate(762.8,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mo" transform="translate(1818.6,0)"><path data-c="2212" d="M84 237T84 250T98 270H679Q694 262 694 250T679 230H98Q84 237 84 250Z"></path></g><g data-mml-node="mn" transform="translate(2596.6,0)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g></g></svg></mjx-container>. For quadratics where it is not so obvious, we need hints to guide us along the way. </p>
<p>We can get insights into the signs of <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.294ex" height="1.025ex" role="img" focusable="false" viewBox="0 -442 572 453"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g></g></g></svg></mjx-container> and <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.097ex" height="1.027ex" role="img" focusable="false" viewBox="0 -443 485 454"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g></g></g></svg></mjx-container> by looking at the product and the sum of coefficients of the quadratic. If the product is positive, then they have the same signs. If the product is negative, they have different signs. This makes intuitive sense. In case the product is positive, the sum tells us whether they are both positive or both negative. </p>
<p>We will use this again when we look at the alternative method to factor a quadratic. First, however, we will look at a different type of quadratic where the coefficient of <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="2.282ex" height="1.912ex" role="img" focusable="false" viewBox="0 -833.9 1008.6 844.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="msup"><g data-mml-node="mi"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mn" transform="translate(605,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g></g></g></svg></mjx-container> is not 1. </p>
<p>Consider the quadratic <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="12.501ex" height="2.072ex" role="img" focusable="false" viewBox="0 -833.9 5525.4 915.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="34" d="M462 0Q444 3 333 3Q217 3 199 0H190V46H221Q241 46 248 46T265 48T279 53T286 61Q287 63 287 115V165H28V211L179 442Q332 674 334 675Q336 677 355 677H373L379 671V211H471V165H379V114Q379 73 379 66T385 54Q393 47 442 46H471V0H462ZM293 211V545L74 212L183 211H293Z"></path></g><g data-mml-node="msup" transform="translate(500,0)"><g data-mml-node="mi"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mn" transform="translate(605,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g><g data-mml-node="mo" transform="translate(1730.8,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mn" transform="translate(2731,0)"><path data-c="38" d="M70 417T70 494T124 618T248 666Q319 666 374 624T429 515Q429 485 418 459T392 417T361 389T335 371T324 363L338 354Q352 344 366 334T382 323Q457 264 457 174Q457 95 399 37T249 -22Q159 -22 101 29T43 155Q43 263 172 335L154 348Q133 361 127 368Q70 417 70 494ZM286 386L292 390Q298 394 301 396T311 403T323 413T334 425T345 438T355 454T364 471T369 491T371 513Q371 556 342 586T275 624Q268 625 242 625Q201 625 165 599T128 534Q128 511 141 492T167 463T217 431Q224 426 228 424L286 386ZM250 21Q308 21 350 55T392 137Q392 154 387 169T375 194T353 216T330 234T301 253T274 270Q260 279 244 289T218 306L210 311Q204 311 181 294T133 239T107 157Q107 98 150 60T250 21Z"></path></g><g data-mml-node="mi" transform="translate(3231,0)"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mo" transform="translate(4025.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mn" transform="translate(5025.4,0)"><path data-c="33" d="M127 463Q100 463 85 480T69 524Q69 579 117 622T233 665Q268 665 277 664Q351 652 390 611T430 522Q430 470 396 421T302 350L299 348Q299 347 308 345T337 336T375 315Q457 262 457 175Q457 96 395 37T238 -22Q158 -22 100 21T42 130Q42 158 60 175T105 193Q133 193 151 175T169 130Q169 119 166 110T159 94T148 82T136 74T126 70T118 67L114 66Q165 21 238 21Q293 21 321 74Q338 107 338 175V195Q338 290 274 322Q259 328 213 329L171 330L168 332Q166 335 166 348Q166 366 174 366Q202 366 232 371Q266 376 294 413T322 525V533Q322 590 287 612Q265 626 240 626Q208 626 181 615T143 592T132 580H135Q138 579 143 578T153 573T165 566T175 555T183 540T186 520Q186 498 172 481T127 463Z"></path></g></g></g></svg></mjx-container>. It can be factored as <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="15.909ex" height="2.262ex" role="img" focusable="false" viewBox="0 -750 7031.9 1000"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mo"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(389,0)"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g><g data-mml-node="mi" transform="translate(858,0)"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mo" transform="translate(1652.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(2652.4,0)"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mo" transform="translate(3224.4,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="mo" transform="translate(3613.4,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(4002.4,0)"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g><g data-mml-node="mi" transform="translate(4363.4,0)"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mo" transform="translate(5157.7,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(6157.9,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g><g data-mml-node="mo" transform="translate(6642.9,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g></g></g></svg></mjx-container>. Multiplying the terms gives us <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="22.172ex" height="2.452ex" role="img" focusable="false" viewBox="0 -833.9 9799.9 1083.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g><g data-mml-node="mi" transform="translate(469,0)"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g><g data-mml-node="msup" transform="translate(830,0)"><g data-mml-node="mi"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mn" transform="translate(605,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g><g data-mml-node="mo" transform="translate(2060.8,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mo" transform="translate(3061,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(3450,0)"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g><g data-mml-node="mi" transform="translate(3919,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g><g data-mml-node="mo" transform="translate(4626.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(5626.4,0)"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mi" transform="translate(6198.4,0)"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g><g data-mml-node="mo" transform="translate(6559.4,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="mi" transform="translate(6948.4,0)"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mo" transform="translate(7742.7,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(8742.9,0)"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mi" transform="translate(9314.9,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g></g></g></svg></mjx-container>. As in the previously mentioned quadratic, we can get the product and the sum terms by comparing the quadratic with the general form we just derived. Here <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="6.026ex" height="1.717ex" role="img" focusable="false" viewBox="0 -677 2663.6 759"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g><g data-mml-node="mi" transform="translate(469,0)"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g><g data-mml-node="mo" transform="translate(1107.8,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mn" transform="translate(2163.6,0)"><path data-c="34" d="M462 0Q444 3 333 3Q217 3 199 0H190V46H221Q241 46 248 46T265 48T279 53T286 61Q287 63 287 115V165H28V211L179 442Q332 674 334 675Q336 677 355 677H373L379 671V211H471V165H379V114Q379 73 379 66T385 54Q393 47 442 46H471V0H462ZM293 211V545L74 212L183 211H293Z"></path></g></g></g></svg></mjx-container>, <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="11.183ex" height="1.692ex" role="img" focusable="false" viewBox="0 -666 4943 748"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g><g data-mml-node="mi" transform="translate(469,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g><g data-mml-node="mo" transform="translate(1176.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(2176.4,0)"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mi" transform="translate(2748.4,0)"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g><g data-mml-node="mo" transform="translate(3387.2,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mn" transform="translate(4443,0)"><path data-c="38" d="M70 417T70 494T124 618T248 666Q319 666 374 624T429 515Q429 485 418 459T392 417T361 389T335 371T324 363L338 354Q352 344 366 334T382 323Q457 264 457 174Q457 95 399 37T249 -22Q159 -22 101 29T43 155Q43 263 172 335L154 348Q133 361 127 368Q70 417 70 494ZM286 386L292 390Q298 394 301 396T311 403T323 413T334 425T345 438T355 454T364 471T369 491T371 513Q371 556 342 586T275 624Q268 625 242 625Q201 625 165 599T128 534Q128 511 141 492T167 463T217 431Q224 426 228 424L286 386ZM250 21Q308 21 350 55T392 137Q392 154 387 169T375 194T353 216T330 234T301 253T274 270Q260 279 244 289T218 306L210 311Q204 311 181 294T133 239T107 157Q107 98 150 60T250 21Z"></path></g></g></g></svg></mjx-container> and <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="6.54ex" height="1.69ex" role="img" focusable="false" viewBox="0 -665 2890.6 747"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mi" transform="translate(572,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g><g data-mml-node="mo" transform="translate(1334.8,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mn" transform="translate(2390.6,0)"><path data-c="33" d="M127 463Q100 463 85 480T69 524Q69 579 117 622T233 665Q268 665 277 664Q351 652 390 611T430 522Q430 470 396 421T302 350L299 348Q299 347 308 345T337 336T375 315Q457 262 457 175Q457 96 395 37T238 -22Q158 -22 100 21T42 130Q42 158 60 175T105 193Q133 193 151 175T169 130Q169 119 166 110T159 94T148 82T136 74T126 70T118 67L114 66Q165 21 238 21Q293 21 321 74Q338 107 338 175V195Q338 290 274 322Q259 328 213 329L171 330L168 332Q166 335 166 348Q166 366 174 366Q202 366 232 371Q266 376 294 413T322 525V533Q322 590 287 612Q265 626 240 626Q208 626 181 615T143 592T132 580H135Q138 579 143 578T153 573T165 566T175 555T183 540T186 520Q186 498 172 481T127 463Z"></path></g></g></g></svg></mjx-container>. A small nuance to keep in mind is that if the coefficient of <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="2.282ex" height="1.912ex" role="img" focusable="false" viewBox="0 -833.9 1008.6 844.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="msup"><g data-mml-node="mi"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mn" transform="translate(605,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g></g></g></svg></mjx-container> were negative, we’d factor out a <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="2.891ex" height="1.692ex" role="img" focusable="false" viewBox="0 -666 1278 748"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mo"><path data-c="2212" d="M84 237T84 250T98 270H679Q694 262 694 250T679 230H98Q84 237 84 250Z"></path></g><g data-mml-node="mn" transform="translate(778,0)"><path data-c="31" d="M213 578L200 573Q186 568 160 563T102 556H83V602H102Q149 604 189 617T245 641T273 663Q275 666 285 666Q294 666 302 660V361L303 61Q310 54 315 52T339 48T401 46H427V0H416Q395 3 257 3Q121 3 100 0H88V46H114Q136 46 152 46T177 47T193 50T201 52T207 57T213 61V578Z"></path></g></g></g></svg></mjx-container> to make it positive.</p>
<p>Now we move on to the problem and the method. You’ll find that although the method is tedious, it will remove the element of luck from the process.</p>
<h2 id="Method"><a href="#Method" class="headerlink" title="Method"></a>Method</h2><p>Consider the quadratic <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="18.157ex" height="2.072ex" role="img" focusable="false" viewBox="0 -833.9 8025.4 915.9"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="34" d="M462 0Q444 3 333 3Q217 3 199 0H190V46H221Q241 46 248 46T265 48T279 53T286 61Q287 63 287 115V165H28V211L179 442Q332 674 334 675Q336 677 355 677H373L379 671V211H471V165H379V114Q379 73 379 66T385 54Q393 47 442 46H471V0H462ZM293 211V545L74 212L183 211H293Z"></path><path data-c="39" d="M352 287Q304 211 232 211Q154 211 104 270T44 396Q42 412 42 436V444Q42 537 111 606Q171 666 243 666Q245 666 249 666T257 665H261Q273 665 286 663T323 651T370 619T413 560Q456 472 456 334Q456 194 396 97Q361 41 312 10T208 -22Q147 -22 108 7T68 93T121 149Q143 149 158 135T173 96Q173 78 164 65T148 49T135 44L131 43Q131 41 138 37T164 27T206 22H212Q272 22 313 86Q352 142 352 280V287ZM244 248Q292 248 321 297T351 430Q351 508 343 542Q341 552 337 562T323 588T293 615T246 625Q208 625 181 598Q160 576 154 546T147 441Q147 358 152 329T172 282Q197 248 244 248Z" transform="translate(500,0)"></path></g><g data-mml-node="msup" transform="translate(1000,0)"><g data-mml-node="mi"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mn" transform="translate(605,363) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path></g></g><g data-mml-node="mo" transform="translate(2230.8,0)"><path data-c="2212" d="M84 237T84 250T98 270H679Q694 262 694 250T679 230H98Q84 237 84 250Z"></path></g><g data-mml-node="mn" transform="translate(3231,0)"><path data-c="33" d="M127 463Q100 463 85 480T69 524Q69 579 117 622T233 665Q268 665 277 664Q351 652 390 611T430 522Q430 470 396 421T302 350L299 348Q299 347 308 345T337 336T375 315Q457 262 457 175Q457 96 395 37T238 -22Q158 -22 100 21T42 130Q42 158 60 175T105 193Q133 193 151 175T169 130Q169 119 166 110T159 94T148 82T136 74T126 70T118 67L114 66Q165 21 238 21Q293 21 321 74Q338 107 338 175V195Q338 290 274 322Q259 328 213 329L171 330L168 332Q166 335 166 348Q166 366 174 366Q202 366 232 371Q266 376 294 413T322 525V533Q322 590 287 612Q265 626 240 626Q208 626 181 615T143 592T132 580H135Q138 579 143 578T153 573T165 566T175 555T183 540T186 520Q186 498 172 481T127 463Z"></path><path data-c="31" d="M213 578L200 573Q186 568 160 563T102 556H83V602H102Q149 604 189 617T245 641T273 663Q275 666 285 666Q294 666 302 660V361L303 61Q310 54 315 52T339 48T401 46H427V0H416Q395 3 257 3Q121 3 100 0H88V46H114Q136 46 152 46T177 47T193 50T201 52T207 57T213 61V578Z" transform="translate(500,0)"></path><path data-c="36" d="M42 313Q42 476 123 571T303 666Q372 666 402 630T432 550Q432 525 418 510T379 495Q356 495 341 509T326 548Q326 592 373 601Q351 623 311 626Q240 626 194 566Q147 500 147 364L148 360Q153 366 156 373Q197 433 263 433H267Q313 433 348 414Q372 400 396 374T435 317Q456 268 456 210V192Q456 169 451 149Q440 90 387 34T253 -22Q225 -22 199 -14T143 16T92 75T56 172T42 313ZM257 397Q227 397 205 380T171 335T154 278T148 216Q148 133 160 97T198 39Q222 21 251 21Q302 21 329 59Q342 77 347 104T352 209Q352 289 347 316T329 361Q302 397 257 397Z" transform="translate(1000,0)"></path></g><g data-mml-node="mi" transform="translate(4731,0)"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mo" transform="translate(5525.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mn" transform="translate(6525.4,0)"><path data-c="31" d="M213 578L200 573Q186 568 160 563T102 556H83V602H102Q149 604 189 617T245 641T273 663Q275 666 285 666Q294 666 302 660V361L303 61Q310 54 315 52T339 48T401 46H427V0H416Q395 3 257 3Q121 3 100 0H88V46H114Q136 46 152 46T177 47T193 50T201 52T207 57T213 61V578Z"></path><path data-c="33" d="M127 463Q100 463 85 480T69 524Q69 579 117 622T233 665Q268 665 277 664Q351 652 390 611T430 522Q430 470 396 421T302 350L299 348Q299 347 308 345T337 336T375 315Q457 262 457 175Q457 96 395 37T238 -22Q158 -22 100 21T42 130Q42 158 60 175T105 193Q133 193 151 175T169 130Q169 119 166 110T159 94T148 82T136 74T126 70T118 67L114 66Q165 21 238 21Q293 21 321 74Q338 107 338 175V195Q338 290 274 322Q259 328 213 329L171 330L168 332Q166 335 166 348Q166 366 174 366Q202 366 232 371Q266 376 294 413T322 525V533Q322 590 287 612Q265 626 240 626Q208 626 181 615T143 592T132 580H135Q138 579 143 578T153 573T165 566T175 555T183 540T186 520Q186 498 172 481T127 463Z" transform="translate(500,0)"></path><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z" transform="translate(1000,0)"></path></g></g></g></svg></mjx-container>. Here, <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="7.157ex" height="1.717ex" role="img" focusable="false" viewBox="0 -677 3163.6 759"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g><g data-mml-node="mi" transform="translate(469,0)"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g><g data-mml-node="mo" transform="translate(1107.8,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mn" transform="translate(2163.6,0)"><path data-c="34" d="M462 0Q444 3 333 3Q217 3 199 0H190V46H221Q241 46 248 46T265 48T279 53T286 61Q287 63 287 115V165H28V211L179 442Q332 674 334 675Q336 677 355 677H373L379 671V211H471V165H379V114Q379 73 379 66T385 54Q393 47 442 46H471V0H462ZM293 211V545L74 212L183 211H293Z"></path><path data-c="39" d="M352 287Q304 211 232 211Q154 211 104 270T44 396Q42 412 42 436V444Q42 537 111 606Q171 666 243 666Q245 666 249 666T257 665H261Q273 665 286 663T323 651T370 619T413 560Q456 472 456 334Q456 194 396 97Q361 41 312 10T208 -22Q147 -22 108 7T68 93T121 149Q143 149 158 135T173 96Q173 78 164 65T148 49T135 44L131 43Q131 41 138 37T164 27T206 22H212Q272 22 313 86Q352 142 352 280V287ZM244 248Q292 248 321 297T351 430Q351 508 343 542Q341 552 337 562T323 588T293 615T246 625Q208 625 181 598Q160 576 154 546T147 441Q147 358 152 329T172 282Q197 248 244 248Z" transform="translate(500,0)"></path></g></g></g></svg></mjx-container>, <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="15.206ex" height="1.692ex" role="img" focusable="false" viewBox="0 -666 6721 748"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g><g data-mml-node="mi" transform="translate(469,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g><g data-mml-node="mo" transform="translate(1176.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(2176.4,0)"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mi" transform="translate(2748.4,0)"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g><g data-mml-node="mo" transform="translate(3387.2,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mo" transform="translate(4443,0)"><path data-c="2212" d="M84 237T84 250T98 270H679Q694 262 694 250T679 230H98Q84 237 84 250Z"></path></g><g data-mml-node="mn" transform="translate(5221,0)"><path data-c="33" d="M127 463Q100 463 85 480T69 524Q69 579 117 622T233 665Q268 665 277 664Q351 652 390 611T430 522Q430 470 396 421T302 350L299 348Q299 347 308 345T337 336T375 315Q457 262 457 175Q457 96 395 37T238 -22Q158 -22 100 21T42 130Q42 158 60 175T105 193Q133 193 151 175T169 130Q169 119 166 110T159 94T148 82T136 74T126 70T118 67L114 66Q165 21 238 21Q293 21 321 74Q338 107 338 175V195Q338 290 274 322Q259 328 213 329L171 330L168 332Q166 335 166 348Q166 366 174 366Q202 366 232 371Q266 376 294 413T322 525V533Q322 590 287 612Q265 626 240 626Q208 626 181 615T143 592T132 580H135Q138 579 143 578T153 573T165 566T175 555T183 540T186 520Q186 498 172 481T127 463Z"></path><path data-c="31" d="M213 578L200 573Q186 568 160 563T102 556H83V602H102Q149 604 189 617T245 641T273 663Q275 666 285 666Q294 666 302 660V361L303 61Q310 54 315 52T339 48T401 46H427V0H416Q395 3 257 3Q121 3 100 0H88V46H114Q136 46 152 46T177 47T193 50T201 52T207 57T213 61V578Z" transform="translate(500,0)"></path><path data-c="36" d="M42 313Q42 476 123 571T303 666Q372 666 402 630T432 550Q432 525 418 510T379 495Q356 495 341 509T326 548Q326 592 373 601Q351 623 311 626Q240 626 194 566Q147 500 147 364L148 360Q153 366 156 373Q197 433 263 433H267Q313 433 348 414Q372 400 396 374T435 317Q456 268 456 210V192Q456 169 451 149Q440 90 387 34T253 -22Q225 -22 199 -14T143 16T92 75T56 172T42 313ZM257 397Q227 397 205 380T171 335T154 278T148 216Q148 133 160 97T198 39Q222 21 251 21Q302 21 329 59Q342 77 347 104T352 209Q352 289 347 316T329 361Q302 397 257 397Z" transform="translate(1000,0)"></path></g></g></g></svg></mjx-container>, and <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="8.802ex" height="1.692ex" role="img" focusable="false" viewBox="0 -666 3890.6 748"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mi" transform="translate(572,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g><g data-mml-node="mo" transform="translate(1334.8,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mn" transform="translate(2390.6,0)"><path data-c="31" d="M213 578L200 573Q186 568 160 563T102 556H83V602H102Q149 604 189 617T245 641T273 663Q275 666 285 666Q294 666 302 660V361L303 61Q310 54 315 52T339 48T401 46H427V0H416Q395 3 257 3Q121 3 100 0H88V46H114Q136 46 152 46T177 47T193 50T201 52T207 57T213 61V578Z"></path><path data-c="33" d="M127 463Q100 463 85 480T69 524Q69 579 117 622T233 665Q268 665 277 664Q351 652 390 611T430 522Q430 470 396 421T302 350L299 348Q299 347 308 345T337 336T375 315Q457 262 457 175Q457 96 395 37T238 -22Q158 -22 100 21T42 130Q42 158 60 175T105 193Q133 193 151 175T169 130Q169 119 166 110T159 94T148 82T136 74T126 70T118 67L114 66Q165 21 238 21Q293 21 321 74Q338 107 338 175V195Q338 290 274 322Q259 328 213 329L171 330L168 332Q166 335 166 348Q166 366 174 366Q202 366 232 371Q266 376 294 413T322 525V533Q322 590 287 612Q265 626 240 626Q208 626 181 615T143 592T132 580H135Q138 579 143 578T153 573T165 566T175 555T183 540T186 520Q186 498 172 481T127 463Z" transform="translate(500,0)"></path><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z" transform="translate(1000,0)"></path></g></g></g></svg></mjx-container>. From the guiding hints mentioned in the previous section, we notice that the signs of <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.294ex" height="1.025ex" role="img" focusable="false" viewBox="0 -442 572 453"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g></g></g></svg></mjx-container> and <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.097ex" height="1.027ex" role="img" focusable="false" viewBox="0 -443 485 454"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g></g></g></svg></mjx-container> are the same; they are either both positive or both negative. We begin the method be defining a function <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="4.595ex" height="2.262ex" role="img" focusable="false" viewBox="0 -750 2031 1000"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mtext"><path data-c="46" d="M128 619Q121 626 117 628T101 631T58 634H25V680H582V676Q584 670 596 560T610 444V440H570V444Q563 493 561 501Q555 538 543 563T516 601T477 622T431 631T374 633H334H286Q252 633 244 631T233 621Q232 619 232 490V363H284Q287 363 303 363T327 364T349 367T372 373T389 385Q407 403 410 459V480H450V200H410V221Q407 276 389 296Q381 303 371 307T348 313T327 316T303 317T284 317H232V189L233 61Q240 54 245 52T270 48T333 46H360V0H348Q324 3 182 3Q51 3 36 0H25V46H58Q100 47 109 49T128 61V619Z"></path></g><g data-mml-node="mo" transform="translate(653,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(1042,0)"><path data-c="1D45B" d="M21 287Q22 293 24 303T36 341T56 388T89 425T135 442Q171 442 195 424T225 390T231 369Q231 367 232 367L243 378Q304 442 382 442Q436 442 469 415T503 336T465 179T427 52Q427 26 444 26Q450 26 453 27Q482 32 505 65T540 145Q542 153 560 153Q580 153 580 145Q580 144 576 130Q568 101 554 73T508 17T439 -10Q392 -10 371 17T350 73Q350 92 386 193T423 345Q423 404 379 404H374Q288 404 229 303L222 291L189 157Q156 26 151 16Q138 -11 108 -11Q95 -11 87 -5T76 7T74 17Q74 30 112 180T152 343Q153 348 153 366Q153 405 129 405Q91 405 66 305Q60 285 60 284Q58 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mo" transform="translate(1642,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g></g></g></svg></mjx-container> which returns a set of pairs of all the factors of <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.357ex" height="1.025ex" role="img" focusable="false" viewBox="0 -442 600 453"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D45B" d="M21 287Q22 293 24 303T36 341T56 388T89 425T135 442Q171 442 195 424T225 390T231 369Q231 367 232 367L243 378Q304 442 382 442Q436 442 469 415T503 336T465 179T427 52Q427 26 444 26Q450 26 453 27Q482 32 505 65T540 145Q542 153 560 153Q580 153 580 145Q580 144 576 130Q568 101 554 73T508 17T439 -10Q392 -10 371 17T350 73Q350 92 386 193T423 345Q423 404 379 404H374Q288 404 229 303L222 291L189 157Q156 26 151 16Q138 -11 108 -11Q95 -11 87 -5T76 7T74 17Q74 30 112 180T152 343Q153 348 153 366Q153 405 129 405Q91 405 66 305Q60 285 60 284Q58 278 41 278H27Q21 284 21 287Z"></path></g></g></g></svg></mjx-container>. Therefore, we can write <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="5.115ex" height="2.262ex" role="img" focusable="false" viewBox="0 -750 2261 1000"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mtext"><path data-c="46" d="M128 619Q121 626 117 628T101 631T58 634H25V680H582V676Q584 670 596 560T610 444V440H570V444Q563 493 561 501Q555 538 543 563T516 601T477 622T431 631T374 633H334H286Q252 633 244 631T233 621Q232 619 232 490V363H284Q287 363 303 363T327 364T349 367T372 373T389 385Q407 403 410 459V480H450V200H410V221Q407 276 389 296Q381 303 371 307T348 313T327 316T303 317T284 317H232V189L233 61Q240 54 245 52T270 48T333 46H360V0H348Q324 3 182 3Q51 3 36 0H25V46H58Q100 47 109 49T128 61V619Z"></path></g><g data-mml-node="mo" transform="translate(653,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(1042,0)"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g><g data-mml-node="mi" transform="translate(1511,0)"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g><g data-mml-node="mo" transform="translate(1872,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g></g></g></svg></mjx-container> and <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="5.629ex" height="2.262ex" role="img" focusable="false" viewBox="0 -750 2488 1000"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mtext"><path data-c="46" d="M128 619Q121 626 117 628T101 631T58 634H25V680H582V676Q584 670 596 560T610 444V440H570V444Q563 493 561 501Q555 538 543 563T516 601T477 622T431 631T374 633H334H286Q252 633 244 631T233 621Q232 619 232 490V363H284Q287 363 303 363T327 364T349 367T372 373T389 385Q407 403 410 459V480H450V200H410V221Q407 276 389 296Q381 303 371 307T348 313T327 316T303 317T284 317H232V189L233 61Q240 54 245 52T270 48T333 46H360V0H348Q324 3 182 3Q51 3 36 0H25V46H58Q100 47 109 49T128 61V619Z"></path></g><g data-mml-node="mo" transform="translate(653,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(1042,0)"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mi" transform="translate(1614,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g><g data-mml-node="mo" transform="translate(2099,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g></g></g></svg></mjx-container> as follows.</p>
<p align="center"> <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="31.107ex" height="2.262ex" role="img" focusable="false" viewBox="0 -750 13749.1 1000"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mtext"><path data-c="46" d="M128 619Q121 626 117 628T101 631T58 634H25V680H582V676Q584 670 596 560T610 444V440H570V444Q563 493 561 501Q555 538 543 563T516 601T477 622T431 631T374 633H334H286Q252 633 244 631T233 621Q232 619 232 490V363H284Q287 363 303 363T327 364T349 367T372 373T389 385Q407 403 410 459V480H450V200H410V221Q407 276 389 296Q381 303 371 307T348 313T327 316T303 317T284 317H232V189L233 61Q240 54 245 52T270 48T333 46H360V0H348Q324 3 182 3Q51 3 36 0H25V46H58Q100 47 109 49T128 61V619Z"></path></g><g data-mml-node="mo" transform="translate(653,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(1042,0)"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g><g data-mml-node="mi" transform="translate(1511,0)"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g><g data-mml-node="mo" transform="translate(1872,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="mo" transform="translate(2538.8,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mtext" transform="translate(3594.6,0)"><path data-c="46" d="M128 619Q121 626 117 628T101 631T58 634H25V680H582V676Q584 670 596 560T610 444V440H570V444Q563 493 561 501Q555 538 543 563T516 601T477 622T431 631T374 633H334H286Q252 633 244 631T233 621Q232 619 232 490V363H284Q287 363 303 363T327 364T349 367T372 373T389 385Q407 403 410 459V480H450V200H410V221Q407 276 389 296Q381 303 371 307T348 313T327 316T303 317T284 317H232V189L233 61Q240 54 245 52T270 48T333 46H360V0H348Q324 3 182 3Q51 3 36 0H25V46H58Q100 47 109 49T128 61V619Z"></path></g><g data-mml-node="mo" transform="translate(4247.6,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mn" transform="translate(4636.6,0)"><path data-c="34" d="M462 0Q444 3 333 3Q217 3 199 0H190V46H221Q241 46 248 46T265 48T279 53T286 61Q287 63 287 115V165H28V211L179 442Q332 674 334 675Q336 677 355 677H373L379 671V211H471V165H379V114Q379 73 379 66T385 54Q393 47 442 46H471V0H462ZM293 211V545L74 212L183 211H293Z"></path><path data-c="39" d="M352 287Q304 211 232 211Q154 211 104 270T44 396Q42 412 42 436V444Q42 537 111 606Q171 666 243 666Q245 666 249 666T257 665H261Q273 665 286 663T323 651T370 619T413 560Q456 472 456 334Q456 194 396 97Q361 41 312 10T208 -22Q147 -22 108 7T68 93T121 149Q143 149 158 135T173 96Q173 78 164 65T148 49T135 44L131 43Q131 41 138 37T164 27T206 22H212Q272 22 313 86Q352 142 352 280V287ZM244 248Q292 248 321 297T351 430Q351 508 343 542Q341 552 337 562T323 588T293 615T246 625Q208 625 181 598Q160 576 154 546T147 441Q147 358 152 329T172 282Q197 248 244 248Z" transform="translate(500,0)"></path></g><g data-mml-node="mo" transform="translate(5636.6,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="mo" transform="translate(6303.3,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mo" transform="translate(7359.1,0)"><path data-c="7B" d="M434 -231Q434 -244 428 -250H410Q281 -250 230 -184Q225 -177 222 -172T217 -161T213 -148T211 -133T210 -111T209 -84T209 -47T209 0Q209 21 209 53Q208 142 204 153Q203 154 203 155Q189 191 153 211T82 231Q71 231 68 234T65 250T68 266T82 269Q116 269 152 289T203 345Q208 356 208 377T209 529V579Q209 634 215 656T244 698Q270 724 324 740Q361 748 377 749Q379 749 390 749T408 750H428Q434 744 434 732Q434 719 431 716Q429 713 415 713Q362 710 332 689T296 647Q291 634 291 499V417Q291 370 288 353T271 314Q240 271 184 255L170 250L184 245Q202 239 220 230T262 196T290 137Q291 131 291 1Q291 -134 296 -147Q306 -174 339 -192T415 -213Q429 -213 431 -216Q434 -219 434 -231Z"></path></g><g data-mml-node="mo" transform="translate(7859.1,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mn" transform="translate(8248.1,0)"><path data-c="31" d="M213 578L200 573Q186 568 160 563T102 556H83V602H102Q149 604 189 617T245 641T273 663Q275 666 285 666Q294 666 302 660V361L303 61Q310 54 315 52T339 48T401 46H427V0H416Q395 3 257 3Q121 3 100 0H88V46H114Q136 46 152 46T177 47T193 50T201 52T207 57T213 61V578Z"></path></g><g data-mml-node="mo" transform="translate(8748.1,0)"><path data-c="2C" d="M78 35T78 60T94 103T137 121Q165 121 187 96T210 8Q210 -27 201 -60T180 -117T154 -158T130 -185T117 -194Q113 -194 104 -185T95 -172Q95 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data-mml-node="mn" transform="translate(23089.1,0)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 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731Z"></path></g></g></g></svg></mjx-container> </p>
<p>We will now get to the tedious part. We will create combinations of <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.439ex;" xmlns="http://www.w3.org/2000/svg" width="7.287ex" height="1.855ex" role="img" focusable="false" viewBox="0 -626 3221 820"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g><g data-mml-node="mo" transform="translate(469,0)"><path data-c="2C" d="M78 35T78 60T94 103T137 121Q165 121 187 96T210 8Q210 -27 201 -60T180 -117T154 -158T130 -185T117 -194Q113 -194 104 -185T95 -172Q95 -168 106 -156T131 -126T157 -76T173 -3V9L172 8Q170 7 167 6T161 3T152 1T140 0Q113 0 96 17Z"></path></g><g data-mml-node="mi" transform="translate(913.7,0)"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g><g data-mml-node="mo" transform="translate(1274.7,0)"><path data-c="2C" d="M78 35T78 60T94 103T137 121Q165 121 187 96T210 8Q210 -27 201 -60T180 -117T154 -158T130 -185T117 -194Q113 -194 104 -185T95 -172Q95 -168 106 -156T131 -126T157 -76T173 -3V9L172 8Q170 7 167 6T161 3T152 1T140 0Q113 0 96 17Z"></path></g><g data-mml-node="mi" transform="translate(1719.3,0)"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mo" transform="translate(2291.3,0)"><path data-c="2C" d="M78 35T78 60T94 103T137 121Q165 121 187 96T210 8Q210 -27 201 -60T180 -117T154 -158T130 -185T117 -194Q113 -194 104 -185T95 -172Q95 -168 106 -156T131 -126T157 -76T173 -3V9L172 8Q170 7 167 6T161 3T152 1T140 0Q113 0 96 17Z"></path></g><g data-mml-node="mi" transform="translate(2736,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g></g></g></svg></mjx-container>. We pick the first pair of factors of <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.878ex" height="1.441ex" role="img" focusable="false" viewBox="0 -626 830 637"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g><g data-mml-node="mi" transform="translate(469,0)"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g></g></g></svg></mjx-container> and match it with the first pair of factors of <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="2.391ex" height="1.027ex" role="img" focusable="false" viewBox="0 -443 1057 454"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mi" transform="translate(572,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g></g></g></svg></mjx-container>. For the sake of brevity, we will only some of the examples to illustrate the process. </p>
<div class="table-container">
<table>
<thead>
<tr>
<th><mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.023ex;" xmlns="http://www.w3.org/2000/svg" width="1.061ex" height="1.023ex" role="img" focusable="false" viewBox="0 -442 469 452"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g></g></g></svg></mjx-container></th>
<th><mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="0.817ex" height="1.441ex" role="img" focusable="false" viewBox="0 -626 361 637"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g></g></g></svg></mjx-container></th>
<th><mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.294ex" height="1.025ex" role="img" focusable="false" viewBox="0 -442 572 453"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g></g></g></svg></mjx-container></th>
<th><mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.097ex" height="1.027ex" role="img" focusable="false" viewBox="0 -443 485 454"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g></g></g></svg></mjx-container></th>
<th><mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="7.035ex" height="1.602ex" role="img" focusable="false" viewBox="0 -626 3109.4 708"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g><g data-mml-node="mi" transform="translate(469,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g><g data-mml-node="mo" transform="translate(1176.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(2176.4,0)"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mi" transform="translate(2748.4,0)"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g></g></g></svg></mjx-container></th>
</tr>
</thead>
<tbody>
<tr>
<td>7</td>
<td>7</td>
<td>2</td>
<td>66</td>
<td>476</td>
</tr>
<tr>
<td>7</td>
<td>7</td>
<td>-2</td>
<td>-66</td>
<td>-476</td>
</tr>
<tr>
<td>7</td>
<td>7</td>
<td>66</td>
<td>2</td>
<td>476</td>
</tr>
<tr>
<td>7</td>
<td>7</td>
<td>-66</td>
<td>-2</td>
<td>-476</td>
</tr>
</tbody>
</table>
</div>
<p>Notice how we swap the values of <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.294ex" height="1.025ex" role="img" focusable="false" viewBox="0 -442 572 453"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g></g></g></svg></mjx-container> and <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.097ex" height="1.027ex" role="img" focusable="false" viewBox="0 -443 485 454"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g></g></g></svg></mjx-container> in the columns above. This is because we’re trying to find the product <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="7.035ex" height="1.602ex" role="img" focusable="false" viewBox="0 -626 3109.4 708"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g><g data-mml-node="mi" transform="translate(469,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g><g data-mml-node="mo" transform="translate(1176.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(2176.4,0)"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mi" transform="translate(2748.4,0)"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g></g></g></svg></mjx-container> and its value will change depending on what the value of <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.294ex" height="1.025ex" role="img" focusable="false" viewBox="0 -442 572 453"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g></g></g></svg></mjx-container> and <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.097ex" height="1.027ex" role="img" focusable="false" viewBox="0 -443 485 454"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g></g></g></svg></mjx-container> are. Similarly, we’ll have to swap the values of <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.023ex;" xmlns="http://www.w3.org/2000/svg" width="1.061ex" height="1.023ex" role="img" focusable="false" viewBox="0 -442 469 452"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g></g></g></svg></mjx-container> and <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="0.817ex" height="1.441ex" role="img" focusable="false" viewBox="0 -626 361 637"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g></g></g></svg></mjx-container>; this is not apparent in the table above because both the values are <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.05ex;" xmlns="http://www.w3.org/2000/svg" width="1.131ex" height="1.579ex" role="img" focusable="false" viewBox="0 -676 500 698"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mn"><path data-c="37" d="M55 458Q56 460 72 567L88 674Q88 676 108 676H128V672Q128 662 143 655T195 646T364 644H485V605L417 512Q408 500 387 472T360 435T339 403T319 367T305 330T292 284T284 230T278 162T275 80Q275 66 275 52T274 28V19Q270 2 255 -10T221 -22Q210 -22 200 -19T179 0T168 40Q168 198 265 368Q285 400 349 489L395 552H302Q128 552 119 546Q113 543 108 522T98 479L95 458V455H55V458Z"></path></g></g></g></svg></mjx-container>. We will have to continue on with the table since we we are yet to find a combination of numbers which equals <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="5.154ex" height="1.692ex" role="img" focusable="false" viewBox="0 -666 2278 748"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mo"><path data-c="2212" d="M84 237T84 250T98 270H679Q694 262 694 250T679 230H98Q84 237 84 250Z"></path></g><g data-mml-node="mn" transform="translate(778,0)"><path data-c="33" d="M127 463Q100 463 85 480T69 524Q69 579 117 622T233 665Q268 665 277 664Q351 652 390 611T430 522Q430 470 396 421T302 350L299 348Q299 347 308 345T337 336T375 315Q457 262 457 175Q457 96 395 37T238 -22Q158 -22 100 21T42 130Q42 158 60 175T105 193Q133 193 151 175T169 130Q169 119 166 110T159 94T148 82T136 74T126 70T118 67L114 66Q165 21 238 21Q293 21 321 74Q338 107 338 175V195Q338 290 274 322Q259 328 213 329L171 330L168 332Q166 335 166 348Q166 366 174 366Q202 366 232 371Q266 376 294 413T322 525V533Q322 590 287 612Q265 626 240 626Q208 626 181 615T143 592T132 580H135Q138 579 143 578T153 573T165 566T175 555T183 540T186 520Q186 498 172 481T127 463Z"></path><path data-c="31" d="M213 578L200 573Q186 568 160 563T102 556H83V602H102Q149 604 189 617T245 641T273 663Q275 666 285 666Q294 666 302 660V361L303 61Q310 54 315 52T339 48T401 46H427V0H416Q395 3 257 3Q121 3 100 0H88V46H114Q136 46 152 46T177 47T193 50T201 52T207 57T213 61V578Z" transform="translate(500,0)"></path><path data-c="36" d="M42 313Q42 476 123 571T303 666Q372 666 402 630T432 550Q432 525 418 510T379 495Q356 495 341 509T326 548Q326 592 373 601Q351 623 311 626Q240 626 194 566Q147 500 147 364L148 360Q153 366 156 373Q197 433 263 433H267Q313 433 348 414Q372 400 396 374T435 317Q456 268 456 210V192Q456 169 451 149Q440 90 387 34T253 -22Q225 -22 199 -14T143 16T92 75T56 172T42 313ZM257 397Q227 397 205 380T171 335T154 278T148 216Q148 133 160 97T198 39Q222 21 251 21Q302 21 329 59Q342 77 347 104T352 209Q352 289 347 316T329 361Q302 397 257 397Z" transform="translate(1000,0)"></path></g></g></g></svg></mjx-container>. The table is quite large so we’ll skip the rest of the entries for the sake of brevity and look at the one which gives us the value we’re looking for. </p>
<div class="table-container">
<table>
<thead>
<tr>
<th><mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.023ex;" xmlns="http://www.w3.org/2000/svg" width="1.061ex" height="1.023ex" role="img" focusable="false" viewBox="0 -442 469 452"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g></g></g></svg></mjx-container></th>
<th><mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="0.817ex" height="1.441ex" role="img" focusable="false" viewBox="0 -626 361 637"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g></g></g></svg></mjx-container></th>
<th><mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.294ex" height="1.025ex" role="img" focusable="false" viewBox="0 -442 572 453"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g></g></g></svg></mjx-container></th>
<th><mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.025ex;" xmlns="http://www.w3.org/2000/svg" width="1.097ex" height="1.027ex" role="img" focusable="false" viewBox="0 -443 485 454"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g></g></g></svg></mjx-container></th>
<th><mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="7.035ex" height="1.602ex" role="img" focusable="false" viewBox="0 -626 3109.4 708"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D460" d="M131 289Q131 321 147 354T203 415T300 442Q362 442 390 415T419 355Q419 323 402 308T364 292Q351 292 340 300T328 326Q328 342 337 354T354 372T367 378Q368 378 368 379Q368 382 361 388T336 399T297 405Q249 405 227 379T204 326Q204 301 223 291T278 274T330 259Q396 230 396 163Q396 135 385 107T352 51T289 7T195 -10Q118 -10 86 19T53 87Q53 126 74 143T118 160Q133 160 146 151T160 120Q160 94 142 76T111 58Q109 57 108 57T107 55Q108 52 115 47T146 34T201 27Q237 27 263 38T301 66T318 97T323 122Q323 150 302 164T254 181T195 196T148 231Q131 256 131 289Z"></path></g><g data-mml-node="mi" transform="translate(469,0)"><path data-c="1D463" d="M173 380Q173 405 154 405Q130 405 104 376T61 287Q60 286 59 284T58 281T56 279T53 278T49 278T41 278H27Q21 284 21 287Q21 294 29 316T53 368T97 419T160 441Q202 441 225 417T249 361Q249 344 246 335Q246 329 231 291T200 202T182 113Q182 86 187 69Q200 26 250 26Q287 26 319 60T369 139T398 222T409 277Q409 300 401 317T383 343T365 361T357 383Q357 405 376 424T417 443Q436 443 451 425T467 367Q467 340 455 284T418 159T347 40T241 -11Q177 -11 139 22Q102 54 102 117Q102 148 110 181T151 298Q173 362 173 380Z"></path></g><g data-mml-node="mo" transform="translate(1176.2,0)"><path data-c="2B" d="M56 237T56 250T70 270H369V420L370 570Q380 583 389 583Q402 583 409 568V270H707Q722 262 722 250T707 230H409V-68Q401 -82 391 -82H389H387Q375 -82 369 -68V230H70Q56 237 56 250Z"></path></g><g data-mml-node="mi" transform="translate(2176.4,0)"><path data-c="1D462" d="M21 287Q21 295 30 318T55 370T99 420T158 442Q204 442 227 417T250 358Q250 340 216 246T182 105Q182 62 196 45T238 27T291 44T328 78L339 95Q341 99 377 247Q407 367 413 387T427 416Q444 431 463 431Q480 431 488 421T496 402L420 84Q419 79 419 68Q419 43 426 35T447 26Q469 29 482 57T512 145Q514 153 532 153Q551 153 551 144Q550 139 549 130T540 98T523 55T498 17T462 -8Q454 -10 438 -10Q372 -10 347 46Q345 45 336 36T318 21T296 6T267 -6T233 -11Q189 -11 155 7Q103 38 103 113Q103 170 138 262T173 379Q173 380 173 381Q173 390 173 393T169 400T158 404H154Q131 404 112 385T82 344T65 302T57 280Q55 278 41 278H27Q21 284 21 287Z"></path></g><g data-mml-node="mi" transform="translate(2748.4,0)"><path data-c="1D461" d="M26 385Q19 392 19 395Q19 399 22 411T27 425Q29 430 36 430T87 431H140L159 511Q162 522 166 540T173 566T179 586T187 603T197 615T211 624T229 626Q247 625 254 615T261 596Q261 589 252 549T232 470L222 433Q222 431 272 431H323Q330 424 330 420Q330 398 317 385H210L174 240Q135 80 135 68Q135 26 162 26Q197 26 230 60T283 144Q285 150 288 151T303 153H307Q322 153 322 145Q322 142 319 133Q314 117 301 95T267 48T216 6T155 -11Q125 -11 98 4T59 56Q57 64 57 83V101L92 241Q127 382 128 383Q128 385 77 385H26Z"></path></g></g></g></svg></mjx-container></th>
</tr>
</thead>
<tbody>
<tr>
<td>49</td>
<td>1</td>
<td>-22</td>
<td>-6</td>
<td>-316</td>
</tr>
</tbody>
</table>
</div>
<p>We can now write our factors as <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.566ex;" xmlns="http://www.w3.org/2000/svg" width="17.296ex" height="2.262ex" role="img" focusable="false" viewBox="0 -750 7644.9 1000"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mo"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mn" transform="translate(389,0)"><path data-c="34" d="M462 0Q444 3 333 3Q217 3 199 0H190V46H221Q241 46 248 46T265 48T279 53T286 61Q287 63 287 115V165H28V211L179 442Q332 674 334 675Q336 677 355 677H373L379 671V211H471V165H379V114Q379 73 379 66T385 54Q393 47 442 46H471V0H462ZM293 211V545L74 212L183 211H293Z"></path><path data-c="39" d="M352 287Q304 211 232 211Q154 211 104 270T44 396Q42 412 42 436V444Q42 537 111 606Q171 666 243 666Q245 666 249 666T257 665H261Q273 665 286 663T323 651T370 619T413 560Q456 472 456 334Q456 194 396 97Q361 41 312 10T208 -22Q147 -22 108 7T68 93T121 149Q143 149 158 135T173 96Q173 78 164 65T148 49T135 44L131 43Q131 41 138 37T164 27T206 22H212Q272 22 313 86Q352 142 352 280V287ZM244 248Q292 248 321 297T351 430Q351 508 343 542Q341 552 337 562T323 588T293 615T246 625Q208 625 181 598Q160 576 154 546T147 441Q147 358 152 329T172 282Q197 248 244 248Z" transform="translate(500,0)"></path></g><g data-mml-node="mi" transform="translate(1389,0)"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mo" transform="translate(2183.2,0)"><path data-c="2212" d="M84 237T84 250T98 270H679Q694 262 694 250T679 230H98Q84 237 84 250Z"></path></g><g data-mml-node="mn" transform="translate(3183.4,0)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z" transform="translate(500,0)"></path></g><g data-mml-node="mo" transform="translate(4183.4,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g><g data-mml-node="mo" transform="translate(4572.4,0)"><path data-c="28" d="M94 250Q94 319 104 381T127 488T164 576T202 643T244 695T277 729T302 750H315H319Q333 750 333 741Q333 738 316 720T275 667T226 581T184 443T167 250T184 58T225 -81T274 -167T316 -220T333 -241Q333 -250 318 -250H315H302L274 -226Q180 -141 137 -14T94 250Z"></path></g><g data-mml-node="mi" transform="translate(4961.4,0)"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mo" transform="translate(5755.7,0)"><path data-c="2212" d="M84 237T84 250T98 270H679Q694 262 694 250T679 230H98Q84 237 84 250Z"></path></g><g data-mml-node="mn" transform="translate(6755.9,0)"><path data-c="36" d="M42 313Q42 476 123 571T303 666Q372 666 402 630T432 550Q432 525 418 510T379 495Q356 495 341 509T326 548Q326 592 373 601Q351 623 311 626Q240 626 194 566Q147 500 147 364L148 360Q153 366 156 373Q197 433 263 433H267Q313 433 348 414Q372 400 396 374T435 317Q456 268 456 210V192Q456 169 451 149Q440 90 387 34T253 -22Q225 -22 199 -14T143 16T92 75T56 172T42 313ZM257 397Q227 397 205 380T171 335T154 278T148 216Q148 133 160 97T198 39Q222 21 251 21Q302 21 329 59Q342 77 347 104T352 209Q352 289 347 316T329 361Q302 397 257 397Z"></path></g><g data-mml-node="mo" transform="translate(7255.9,0)"><path data-c="29" d="M60 749L64 750Q69 750 74 750H86L114 726Q208 641 251 514T294 250Q294 182 284 119T261 12T224 -76T186 -143T145 -194T113 -227T90 -246Q87 -249 86 -250H74Q66 -250 63 -250T58 -247T55 -238Q56 -237 66 -225Q221 -64 221 250T66 725Q56 737 55 738Q55 746 60 749Z"></path></g></g></g></svg></mjx-container>. This gives us <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.186ex;" xmlns="http://www.w3.org/2000/svg" width="5.442ex" height="1.692ex" role="img" focusable="false" viewBox="0 -666 2405.6 748"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mo" transform="translate(849.8,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mn" transform="translate(1905.6,0)"><path data-c="36" d="M42 313Q42 476 123 571T303 666Q372 666 402 630T432 550Q432 525 418 510T379 495Q356 495 341 509T326 548Q326 592 373 601Q351 623 311 626Q240 626 194 566Q147 500 147 364L148 360Q153 366 156 373Q197 433 263 433H267Q313 433 348 414Q372 400 396 374T435 317Q456 268 456 210V192Q456 169 451 149Q440 90 387 34T253 -22Q225 -22 199 -14T143 16T92 75T56 172T42 313ZM257 397Q227 397 205 380T171 335T154 278T148 216Q148 133 160 97T198 39Q222 21 251 21Q302 21 329 59Q342 77 347 104T352 209Q352 289 347 316T329 361Q302 397 257 397Z"></path></g></g></g></svg></mjx-container> or <mjx-container class="MathJax" jax="SVG"><svg style="vertical-align: -0.816ex;" xmlns="http://www.w3.org/2000/svg" width="6.906ex" height="2.773ex" role="img" focusable="false" viewBox="0 -864.9 3052.7 1225.5"><g stroke="currentColor" fill="currentColor" stroke-width="0" transform="scale(1,-1)"><g data-mml-node="math"><g data-mml-node="mi"><path data-c="1D465" d="M52 289Q59 331 106 386T222 442Q257 442 286 424T329 379Q371 442 430 442Q467 442 494 420T522 361Q522 332 508 314T481 292T458 288Q439 288 427 299T415 328Q415 374 465 391Q454 404 425 404Q412 404 406 402Q368 386 350 336Q290 115 290 78Q290 50 306 38T341 26Q378 26 414 59T463 140Q466 150 469 151T485 153H489Q504 153 504 145Q504 144 502 134Q486 77 440 33T333 -11Q263 -11 227 52Q186 -10 133 -10H127Q78 -10 57 16T35 71Q35 103 54 123T99 143Q142 143 142 101Q142 81 130 66T107 46T94 41L91 40Q91 39 97 36T113 29T132 26Q168 26 194 71Q203 87 217 139T245 247T261 313Q266 340 266 352Q266 380 251 392T217 404Q177 404 142 372T93 290Q91 281 88 280T72 278H58Q52 284 52 289Z"></path></g><g data-mml-node="mo" transform="translate(849.8,0)"><path data-c="3D" d="M56 347Q56 360 70 367H707Q722 359 722 347Q722 336 708 328L390 327H72Q56 332 56 347ZM56 153Q56 168 72 173H708Q722 163 722 153Q722 140 707 133H70Q56 140 56 153Z"></path></g><g data-mml-node="mfrac" transform="translate(1905.6,0)"><g data-mml-node="mn" transform="translate(220,394) scale(0.707)"><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z"></path><path data-c="32" d="M109 429Q82 429 66 447T50 491Q50 562 103 614T235 666Q326 666 387 610T449 465Q449 422 429 383T381 315T301 241Q265 210 201 149L142 93L218 92Q375 92 385 97Q392 99 409 186V189H449V186Q448 183 436 95T421 3V0H50V19V31Q50 38 56 46T86 81Q115 113 136 137Q145 147 170 174T204 211T233 244T261 278T284 308T305 340T320 369T333 401T340 431T343 464Q343 527 309 573T212 619Q179 619 154 602T119 569T109 550Q109 549 114 549Q132 549 151 535T170 489Q170 464 154 447T109 429Z" transform="translate(500,0)"></path></g><g data-mml-node="mn" transform="translate(220,-345) scale(0.707)"><path data-c="34" d="M462 0Q444 3 333 3Q217 3 199 0H190V46H221Q241 46 248 46T265 48T279 53T286 61Q287 63 287 115V165H28V211L179 442Q332 674 334 675Q336 677 355 677H373L379 671V211H471V165H379V114Q379 73 379 66T385 54Q393 47 442 46H471V0H462ZM293 211V545L74 212L183 211H293Z"></path><path data-c="39" d="M352 287Q304 211 232 211Q154 211 104 270T44 396Q42 412 42 436V444Q42 537 111 606Q171 666 243 666Q245 666 249 666T257 665H261Q273 665 286 663T323 651T370 619T413 560Q456 472 456 334Q456 194 396 97Q361 41 312 10T208 -22Q147 -22 108 7T68 93T121 149Q143 149 158 135T173 96Q173 78 164 65T148 49T135 44L131 43Q131 41 138 37T164 27T206 22H212Q272 22 313 86Q352 142 352 280V287ZM244 248Q292 248 321 297T351 430Q351 508 343 542Q341 552 337 562T323 588T293 615T246 625Q208 625 181 598Q160 576 154 546T147 441Q147 358 152 329T172 282Q197 248 244 248Z" transform="translate(500,0)"></path></g><rect width="907.1" height="60" x="120" y="220"></rect></g></g></g></svg></mjx-container>. </p>
<p>That’s it. That’s how we can factor quadratics by creating combinations of the factors of their coefficients.</p>
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<article id="post-Scaling-Python-Microservices-Part-3" class="article article-type-post" itemscope itemprop="blogPost">
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<a href="/2024/05/19/Scaling-Python-Microservices-Part-3/" class="article-date">
<time datetime="2024-05-19T12:05:46.000Z" itemprop="datePublished">2024-05-19</time>
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<a class="article-title" href="/2024/05/19/Scaling-Python-Microservices-Part-3/">Scaling Python Microservices Part 3</a>
</h1>
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<div class="article-entry" itemprop="articleBody">
<p>In a <a href="/2024/03/21/Setting-up-a-Python-microservice/">previous blog post</a> we’d seen how to use OpenTelemetry and Parca to instrument two microservcies. Imagine that our architecture has grown and we now have many microservices. For example, there is a microservice that is used to send emails, another which keeps track of user profile information, etc. We’d previously hardcoded the HTTP address of the second microservice to make a call from the first microservice. We could have, in a production environment, added a DNS entry which points to the load balancer and used that instead. However, when there are many microservcies, it becomes cumbersome to add these entries. Furthermore, any new microservice which depends on another microservice now needs to have the address as a part of its configuration. Maintaining a single repository, which can be used to find the microservices and their addresses, becomes difficult to maintain. An easier way to find services is to use service discovery - a dynamic way for one service to find another. In this post we’ll modify the previous architecture and add service discovery using Zookeeper. </p>
<h2 id="Before-We-Begin"><a href="#Before-We-Begin" class="headerlink" title="Before We Begin"></a>Before We Begin</h2><p>In a nutshell, we’ll use Zookeeper for service registration and discovery. We’ll modify our <code>create_app</code> factory function to make one more function call which registers the service as it starts. The function call creates an ephemeral node in Zookeeper at a specified path and stores the host and port. Any service which needs to find another service looks for it on the same path. We’ll create a small library for all of this which will make things easier.</p>
<h2 id="Getting-Started"><a href="#Getting-Started" class="headerlink" title="Getting Started"></a>Getting Started</h2><p>We’ll begin by creating a simple attr class to represent a service. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="meta">@define(<span class="params">frozen=<span class="literal">True</span></span>)</span></span><br><span class="line"><span class="keyword">class</span> <span class="title class_">Service</span>:</span><br><span class="line"> host: <span class="built_in">str</span></span><br><span class="line"> port: <span class="built_in">int</span></span><br></pre></td></tr></table></figure>
<p>We’ll be using the <code>kazoo</code> Python library to interact with Zookeeper. The next step is to create a private variable which will be used to store the Zookeeper client. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">_zk: KazooClient | <span class="literal">None</span> = <span class="literal">None</span></span><br></pre></td></tr></table></figure>
<p>Next we’ll add the function which will be called as a part of the <code>create_app</code> factory function. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">init_zookeeper_and_register</span>():</span><br><span class="line"> _init_zookeeper()</span><br><span class="line"> _register_service()</span><br></pre></td></tr></table></figure>
<p>In this function we’ll first initialize the connection to Zookeeper and then register our service. We’ll see both of these functions next, starting with the one to init Zookeeper. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">_init_zookeeper</span>():</span><br><span class="line"> <span class="keyword">global</span> _zk</span><br><span class="line"></span><br><span class="line"> <span class="keyword">if</span> <span class="keyword">not</span> _zk:</span><br><span class="line"> _zk = KazooClient(hosts=<span class="string">'127.0.0.1:2181'</span>)</span><br><span class="line"> _zk.start(timeout=<span class="number">5</span>)</span><br><span class="line"> _zk.add_listener(_state_change_listener)</span><br></pre></td></tr></table></figure>
<p>The <code>_zk</code> variable is meant to be a singleton. I was unable to find whether this is thread-safe or not but for the sake of this post we’ll assume it is. The <code>start</code> method creates a connection to Zookeeper synchronously and raises an error if no connection could be made in <code>timeout</code> seconds. We also add a listener to respond to changes in the state of a Zookeeper connection. This enables us to respond to scenarios where the connection drops momentarily. Since we’ll be creating ephemeral nodes in Zookeeper, they’ll be removed in the case of a session loss and would need to be recreated. In the listener we recreate the node upon a successful reconnection. </p>
<p>Next we’ll look at the function to register the service. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">_register_service</span>():</span><br><span class="line"> <span class="keyword">global</span> _zk</span><br><span class="line"></span><br><span class="line"> service = os.environ.get(<span class="string">"SERVICE"</span>)</span><br><span class="line"> host = socket.getfqdn()</span><br><span class="line"> port = os.environ.get(<span class="string">"PORT"</span>)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">assert</span> service</span><br><span class="line"> <span class="keyword">assert</span> host</span><br><span class="line"> <span class="keyword">assert</span> port</span><br><span class="line"></span><br><span class="line"> identifier = <span class="built_in">str</span>(uuid4())</span><br><span class="line"> path = <span class="string">f"/providers/<span class="subst">{service}</span>/<span class="subst">{identifier}</span>"</span></span><br><span class="line"> data = {<span class="string">"host"</span>: host, <span class="string">"port"</span>: <span class="built_in">int</span>(port)}</span><br><span class="line"> data_bytes = json.dumps(data).encode(<span class="string">"utf-8"</span>)</span><br><span class="line"></span><br><span class="line"> _zk.create(path, data_bytes, ephemeral=<span class="literal">True</span>, makepath=<span class="literal">True</span>)</span><br></pre></td></tr></table></figure>
<p>We get the name of the service and the port it is running on as environment variables. The host is retrieved as the fully-qualified domain name of the machine we’re on. Although the example is running on my local machine, it may work on a cloud provider like AWS. We then create a UUID identifier for the service, and a path on which the service will be registered. The information stored on the path is a JSON containing the host and the port of the service. Finally, we create an ephemeral node on the path and store the host and port. </p>
<p>Next we’ll look at the function which handles changes in connection state. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">_state_change_listener</span>(<span class="params">state</span>):</span><br><span class="line"> <span class="keyword">if</span> state == KazooState.CONNECTED:</span><br><span class="line"> _register_service()</span><br></pre></td></tr></table></figure>
<p>We simply re-register the service upon reconnection. </p>
<p>Finally, we’ll look at the function which retrieves an instance of the service from Zookeeper. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br><span class="line">18</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">get_service_from_zookeeper</span>(<span class="params">service: <span class="built_in">str</span></span>) -> Service | <span class="literal">None</span>:</span><br><span class="line"> <span class="keyword">global</span> _zk</span><br><span class="line"> <span class="keyword">assert</span> _zk</span><br><span class="line"></span><br><span class="line"> path = <span class="string">f"/providers/<span class="subst">{service}</span>"</span></span><br><span class="line"> children = _zk.get_children(path)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">if</span> <span class="keyword">not</span> children:</span><br><span class="line"> <span class="keyword">return</span> <span class="literal">None</span></span><br><span class="line"></span><br><span class="line"> idx = random.randint(<span class="number">0</span>, <span class="built_in">len</span>(children) - <span class="number">1</span>)</span><br><span class="line"></span><br><span class="line"> child = children[idx]</span><br><span class="line"> config, _ = _zk.get(<span class="string">f"/providers/<span class="subst">{service}</span>/<span class="subst">{child}</span>"</span>)</span><br><span class="line"> config = config.decode(<span class="string">"utf-8"</span>)</span><br><span class="line"> config = json.loads(config)</span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> Service(**config)</span><br></pre></td></tr></table></figure>
<p>To get a service we get all the children at the path <code>/providers/SERVICE_NAME</code>. This returns a list of UUIDs, each of which represents an instance of the service. We randomly pick one of these instances and fetch the information associated with it. What we get back is a two-tuple containing the host and port, and an instance of ZStat which we can ignore. We decode and parse the returned information to get an instance of <code>dict</code>. This is then used to return an instance of <code>Service</code>. We can then use this information to make a call to the returned service. </p>
<p>This is all we need to create a small set of utility functions to register and discover services. All we need to do to register the service as a part of the Flask application process is to add a function call in the <code>create_app</code> factory function. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">create_app</span>() -> Flask:</span><br><span class="line"> ...</span><br><span class="line"></span><br><span class="line"> <span class="comment"># -- Initialize Zookeeper and register the service.</span></span><br><span class="line"> init_zookeeper_and_register()</span><br><span class="line"></span><br><span class="line"> <span class="keyword">return</span> app</span><br><span class="line"></span><br></pre></td></tr></table></figure>
<p>Finally, we’ll retrieve the information about the second service in the first service right before we make the call. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">def</span> <span class="title function_">make_request</span>() -> <span class="built_in">dict</span>:</span><br><span class="line"> service = get_service_from_zookeeper(service=<span class="string">"second"</span>)</span><br><span class="line"> url = <span class="string">f"http://<span class="subst">{service.host}</span>:<span class="subst">{service.port}</span>"</span></span><br><span class="line"> ...</span><br></pre></td></tr></table></figure>
<p>As an aside, the service will automatically be deregistered once it stops running. This is because we created an ephemeral node in Zookeeper and it only persists as long as the session that created it is alive. When the service stops, the session is disconnected, and the node is removed from Zookeeper.</p>
<h3 id="Rationale"><a href="#Rationale" class="headerlink" title="Rationale"></a>Rationale</h3><p>The rationale behind registering and discovering services from Zookeeper is to make it easy to create new services and to find the ones that we need. It’s even more convenient when there is a shared library which contains the code that we saw above. For the sake of simplicity, we’ll assume all our services are written in Python and there is a single library that we need. The library could also contain an enum that represents all the services that are registered with Zookeeper. For example, to make a call to an email microservice, we could have code that looks like the following. </p>
<figure class="highlight python"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br></pre></td><td class="code"><pre><span class="line">email_service = Service.EMAIL_SERVICE.value</span><br><span class="line">service = get_service_from_zookeeper(service=email_service)</span><br></pre></td></tr></table></figure>
<p>This, in my opinion, is much simpler than adding a DNS entry. The benefits add up over time and result in code that is both readable and maintainable. </p>
<p>That’s it. That’s how we can register and retrieve services from Zookeeper. <a target="_blank" rel="noopener" href="https://github.com/thescalaguy/microservice">Code is available on Github.</a></p>
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<a class="article-title" href="/2024/05/12/Scaling-Python-Microservices-Part-2/">Scaling Python Microservices Part 2</a>
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<p>In one of the <a href="/2024/03/25/Scaling-Python-Microservices/">previous posts</a> we saw how we can scale a Python microservice and allow it to connect, theoretically, to an infinite number of databases. The way we did this is by fetching the database connection information at runtime from another microservice using the unique identifier of the customer. This allowed us to scale horizontally to some extent. However, there is still the limitation that the data of the customer may be so large that it would exceed the limit of the database when it is scaled vertically. In this post we’ll look at how to extend the architecture we saw previously and shard the data across servers. We’ll continue to use relational databases and see how we can shard the data using Postgres <code>PARTITION BY</code>.</p>
<h2 id="Before-We-Begin"><a href="#Before-We-Begin" class="headerlink" title="Before We Begin"></a>Before We Begin</h2><p>The gist of scaling by sharding is to split the table into multiple partitions and let each of these be hosted on a separate host. For the purpose of this post we’ll use a simple setup that consists of four partitions that are spread over two hosts. We’ll use Postgres’ Foreign Data Wrapper (FDW) to connect one instance of Postgres to another instance of Postgres. We’ll store partitions in both these hosts, and create a table which uses these partitions. Querying this table would allow us to query data from all the partitions. </p>
<h2 id="Getting-Started"><a href="#Getting-Started" class="headerlink" title="Getting Started"></a>Getting Started</h2><p>My setup has two instances of Postgres, both of which will host partitions. One of them will also contain the base table which will use these partitions. We’ll begin by logging into the first instance and creating the FDW extension which ships natively with Postgres. </p>
<figure class="highlight sql"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">CREATE</span> EXTENSION postgres_fdw;</span><br></pre></td></tr></table></figure>
<p>Next, we’ll tell the first instance that there is a second instance of Postgres that we can connect to. Since both of these instances are running as Docker containers, I will use the hostname in the SQL query. </p>
<figure class="highlight sql"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line"><span class="keyword">CREATE</span> SERVER postgres_5 <span class="keyword">FOREIGN</span> DATA WRAPPER postgres_fdw OPTIONS (host <span class="string">'postgres_5'</span>, dbname <span class="string">'postgres'</span>);</span><br></pre></td></tr></table></figure>