Finding The Inverse Equation Of Y=2x² A Step-by-Step Guide

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In the realm of mathematics, understanding the concept of inverse functions is crucial, especially when dealing with quadratic equations. Today, we'll delve into the process of finding the inverse of a function, focusing specifically on the equation y = 2x². Our goal is to identify which equation correctly represents the simplified form for finding this inverse. To achieve this, we will explore the fundamental principles behind inverse functions and apply them step-by-step to the given equation. This comprehensive guide will not only provide the answer but also illuminate the underlying concepts, ensuring a clear understanding of how to find inverses of quadratic functions. So, let's embark on this mathematical journey and unravel the mysteries of inverse functions!

Understanding Inverse Functions

Before diving into the specific equation, it's essential to grasp the core concept of inverse functions. An inverse function essentially undoes the original function. If a function f takes an input x and produces an output y, the inverse function, denoted as f⁻¹, takes y as input and returns x. This relationship can be expressed mathematically as: if f(x) = y, then f⁻¹(y) = x. The process of finding an inverse function involves swapping the roles of x and y and then solving for y. This exchange reflects the fundamental idea of reversing the function's operation. To truly master the concept of inverse functions, one must appreciate this reversal of roles and the subsequent algebraic manipulations required to isolate the new y. Understanding this core principle is the key to navigating the complexities of finding inverses, especially when dealing with more intricate functions. Let's now see how this principle applies to our quadratic equation.

Steps to Find the Inverse Function

To find the inverse of a function, we follow a systematic approach that ensures accuracy and clarity. Here's a breakdown of the steps involved, which we will later apply to our specific equation, y = 2x²:

  1. Swap x and y: The first and most crucial step is to interchange the variables x and y. This reflects the core concept of inverting the function, where the input becomes the output and vice versa. By swapping the variables, we set the stage for solving for the new y, which will represent the inverse function.
  2. Solve for y: After swapping x and y, the next step is to isolate y on one side of the equation. This involves using algebraic manipulations to undo the operations performed on y. The specific steps will vary depending on the complexity of the original function, but the goal remains the same: to express y in terms of x.
  3. Express as f⁻¹(x): Once y is isolated, we can express the inverse function using the notation f⁻¹(x). This notation clearly indicates that we are dealing with the inverse of the original function f(x) and that the variable x is the input to this inverse function. This final step solidifies our understanding of the inverse function and its relationship to the original function.

These steps provide a clear roadmap for finding the inverse of any function. Now, let's apply these steps to our specific equation and see how they work in practice.

Applying the Steps to y = 2x²

Now, let's put our understanding of inverse functions and the steps involved into action. We'll apply these principles to the equation y = 2x² to determine its inverse. This process will not only reveal the correct equation from the given options but also solidify our understanding of how to find inverses of quadratic functions. By meticulously following each step, we'll gain a deeper appreciation for the mechanics of inverse function derivation.

Step 1: Swap x and y

Following the first step in our process, we begin by swapping the variables x and y in the equation y = 2x². This interchange is the cornerstone of finding inverse functions, as it reverses the roles of input and output. After swapping, our equation transforms into:

x = 2y²

This seemingly simple step is the foundation upon which the rest of the solution is built. It's crucial to understand that this swap represents the fundamental shift from the original function to its inverse. With the variables swapped, we are now poised to solve for y, which will represent the inverse function.

Step 2: Solve for y

Having swapped x and y, our next objective is to isolate y on one side of the equation. This involves a series of algebraic manipulations designed to undo the operations performed on y. Starting with the equation x = 2y², we'll methodically work towards isolating y.

First, we need to get rid of the coefficient 2 that's multiplying . To do this, we divide both sides of the equation by 2:

x / 2 = y²

Now, we have isolated, but we need to find y. To undo the square, we take the square root of both sides of the equation:

√(x / 2) = √y²

This simplifies to:

±√(x / 2) = y

It's crucial to remember that when taking the square root, we must consider both the positive and negative roots. This is because both the positive and negative values, when squared, will yield the same result. This consideration is particularly important when dealing with quadratic functions and their inverses.

Step 3: Express as f⁻¹(x)

Now that we have solved for y, we can express the inverse function using the standard notation f⁻¹(x). This notation clearly indicates that we are dealing with the inverse of the original function. Our solution for y was:

y = ±√(x / 2)

Therefore, we can express the inverse function as:

f⁻¹(x) = ±√(x / 2)

This equation represents the inverse of the original function y = 2x². It's important to note the presence of both positive and negative roots, which is a characteristic feature of the inverse of a quadratic function. This final step completes our journey of finding the inverse, and we now have a clear representation of the inverse function.

Identifying the Correct Equation

Now that we have derived the inverse function, let's revisit the original question and identify which of the given equations can be simplified to find the inverse of y = 2x². We'll compare our derived inverse function, f⁻¹(x) = ±√(x / 2), with the provided options to determine the correct match. This comparison will not only answer the question but also reinforce our understanding of the relationship between the original function and its inverse.

The original options were:

  • 1/y = 2x²
  • y = (1/2)x²
  • -y = 2x²
  • x = 2y²

Analyzing the Options

Let's examine each option in light of our derived inverse function:

  • 1/y = 2x²: This equation represents the reciprocal of the original function, not the inverse. It does not involve swapping x and y, which is a fundamental step in finding the inverse.
  • y = (1/2)x²: This equation is a vertical compression of the original function, not its inverse. It does not involve swapping x and y and solving for the new y.
  • -y = 2x²: This equation represents a reflection of the original function across the x-axis, not its inverse. Again, it lacks the crucial step of swapping x and y.
  • x = 2y²: This equation is precisely the result we obtained after swapping x and y in the original equation. This is the key step in finding the inverse function.

The Correct Equation

Based on our analysis, the equation that can be simplified to find the inverse of y = 2x² is:

x = 2y²

This equation represents the intermediate step where we have swapped x and y and are ready to solve for y to obtain the explicit form of the inverse function. This confirms our understanding of the process and highlights the importance of swapping variables when finding inverses.

Conclusion

In conclusion, the equation x = 2y² is the correct choice as it represents the crucial step of swapping x and y in the original equation y = 2x², which is the foundation for finding the inverse function. By following the steps of swapping variables and solving for the new y, we successfully derived the inverse function and identified the correct equation from the given options. This exercise not only answers the specific question but also reinforces the fundamental principles of finding inverse functions, especially in the context of quadratic equations. Understanding these concepts is crucial for success in mathematics, and this step-by-step guide provides a solid foundation for further exploration of inverse functions and related topics. Remember, the key to mastering mathematics lies in understanding the underlying principles and applying them systematically to solve problems.