Chapter 12: Problem 36
Find the inverse of each one-to-one function. $$ f(x)=\sqrt[3]{x+1} $$
Short Answer
Expert verified
The inverse function is \( f^{-1}(x) = x^3 - 1 \).
Step by step solution
01
Understand the Function
The given function is \( f(x) = \sqrt[3]{x+1} \). It is a cube root function shifted 1 unit to the left. Since it is a cube root function, it is one-to-one and therefore has an inverse.
02
Write Function as Equation
To find the inverse, set \( f(x) = y \), which gives \( y = \sqrt[3]{x+1} \). This equation represents the function in terms of \( y \) and \( x \).
03
Swap Variables
Swap \( x \) and \( y \) to begin solving for the inverse: \( x = \sqrt[3]{y+1} \). This is the standard procedure for finding the inverse of a function.
04
Solve for the New Dependent Variable
To isolate \( y \), cube both sides of the equation to remove the cube root: \( x^3 = y+1 \).
05
Isolate the Dependent Variable
Subtract 1 from both sides to solve for \( y \): \( y = x^3 - 1 \). This equation represents the inverse of the original function.
06
Rewrite as Inverse Function
Write the inverse function using function notation: \( f^{-1}(x) = x^3 - 1 \).
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Cube Root Functions
Cube root functions are a special type of radical function. These functions involve the cube root of an expression, typically written as \( f(x) = \sqrt[3]{x} \). One important aspect of cube root functions is their domain and range. Unlike square root functions, which are only defined for non-negative inputs, cube root functions accept all real numbers as inputs. This property makes them more versatile and ensures that every cube root function is a one-to-one function, which is great when finding inverses.
For instance, the function given in our exercise is a slight variation: \( f(x) = \sqrt[3]{x+1} \). This indicates a horizontal shift of 1 unit to the left. While the basic cube root function passes through the origin, this shifted version passes through the point \((-1, 0)\). Recognizing these shifts is critical when graphing or finding inverses.
For instance, the function given in our exercise is a slight variation: \( f(x) = \sqrt[3]{x+1} \). This indicates a horizontal shift of 1 unit to the left. While the basic cube root function passes through the origin, this shifted version passes through the point \((-1, 0)\). Recognizing these shifts is critical when graphing or finding inverses.
One-to-One Functions
A function is called one-to-one (or injective) if each output value corresponds to exactly one input. In simpler terms, no two different x-values will produce the same y-value. This property is crucial for finding inverse functions because it guarantees that the inverse will also be a function.One way to determine if a function is one-to-one is to apply the Horizontal Line Test. If any horizontal line crosses the graph of the function at more than one point, the function isn’t one-to-one.
For cube root functions, like \( f(x) = \sqrt[3]{x+1} \), the graph continuously increases or decreases without turning back, ensuring that each input leads to a unique output. Thus, we are assured that the inverse will also be a valid function.
For cube root functions, like \( f(x) = \sqrt[3]{x+1} \), the graph continuously increases or decreases without turning back, ensuring that each input leads to a unique output. Thus, we are assured that the inverse will also be a valid function.
Solving Equations
Solving equations is a process to find the value of unknown variables that satisfies the equation. When finding inverses, this process is outlined by several steps, as shown in our exercise.Here's a brief overview of what we do to solve \( y = \sqrt[3]{x+1} \) for the inverse:
- Write as an Equation: Replace \( f(x) \) with \( y \) to express the function as an equation in \( y \) and \( x \).
- Swap Variables: Exchange the roles of \( x \) and \( y \), giving \( x = \sqrt[3]{y+1} \).
- Isolate the Variable: To solve for \( y \), cube both sides to get \( x^3 = y + 1 \), then rearrange to find \( y = x^3 - 1 \).