How to Find Inverse of a Function? (+FREE Worksheet!)
Since an inverse function essentially undoes the effects of the original function, you need to learn how to use them. Therefore, in this article, we have tried to acquaint you with the method of using inverse functions.

Related Topics
- How to Add and Subtract Functions
- How to Multiply and Dividing Functions
- How to Solve Function Notation
- How to Solve Composition of Functions
Definition of Function Inverses
- An inverse function is a function that reverses another function: if the function \(f\) applied to an input \(x\) gives a result of \(y\), then applying its inverse function \(g\) to \(y\) gives the result \(x\).
\(f(x)=y\) if and only if \(g(y)=x\) - The inverse function of \(f(x)\) is usually shown by \(f^{-1} (x)\).
Examples
Function Inverses – Example 1:
Find the inverse of the function: \(f(x)=2x-1\)
Solution:
First, replace \(f(x)\) with \(y: y=2x-1\), then, replace all \(x^{‘}s\) with \(y\) and all \(y^{‘}s\) with \(x: x=2y-1\), now, solve for \(y: x=2y-1→x+1=2y→\frac{1}{2} x+\frac{1}{2}=y\), Finally replace \(y\) with \(f^{-1} (x): f^{-1} (x)=\frac{1}{2} x+\frac{1}{2}\)
Function Inverses – Example 2:
Find the inverse of the function: \(g(x)=\frac{1}{5} x+3\)
Solution:
First, replace \(g(x)\) with \(y:\) \(y=\frac{1}{5} x+3\), then, replace all \(x^{‘}s\) with \(y\) and all \(y^{‘}s\) with \(x :\)\(x=\frac{1}{5} y+3\) , now, solve for \(y: x=\frac{1}{5} y+3 → x-3=\frac{1}{5} y→5(x-3)=y → 5x-15=y\), Finally replace \(y\) with \(g^{-1}(x) : g^{-1}(x)=5x-15\)
Function Inverses – Example 3:
Find the inverse of the function: \(h(x)=\sqrt{x}+6\)
Solution:
First, replace \(h(x)\) with \(y:\) \(y=\sqrt{x}+6\), then, replace all \(x^{‘}s\) with y and all \(y^{‘}s\) with \(x : x=\sqrt{y}+6\), now, solve for \(y :\) \(x=\sqrt{y}+6\) → \(x-6=\sqrt{y}→(x-6)^2=\sqrt{y}^2→x^2-12x+36=y\) , Finally replace \(y\) with \(h^{-1}(x): h^{-1} (x)=x^2-12x+36\)
Function Inverses – Example 4:
Find the inverse of the function: \(g(x)=\frac{x+5}{4}\)
Solution:
First, replace \(g(x)\) with \(y :\) \(y=\frac{x+5}{4}\) , then, replace all \(x^{‘}s\) with \(y\) and all \(y^{‘}s\) with \(x :\) \(x=\frac{y+5}{4} \), now, solve for \(y:\) \(x=\frac{y+5}{4} \) → \(4x=y+5→4x-5=y\), Finally replace \(y\) with \( g^{-1}(x) : g^{-1}(x)=4x-5\)
Exercises for Function Inverses
Find the inverse of each function.
- \(\color{blue}{f(x)=\frac{1}{x}-3}\)
\(\color{blue}{f^{-1} (x)=}\)________ - \(\color{blue}{g(x)=2x^3-5}\)
\(\color{blue}{g^{-1} (x)=}\)________ - \(\color{blue}{h(x)=10x}\)
\(\color{blue}{h^{-1} (x)=}\)________ - \(\color{blue}{f(x)=\sqrt{x}-4}\)
\(\color{blue}{f^{-1} (x)=}\)________ - \(\color{blue}{f(x)=3x^2+2}\)
\(\color{blue}{f^{-1} (x)=}\)________ - \(\color{blue}{h(x)=22x}\)
\(\color{blue}{h^{-1} (x)=}\)________

- \(\color{blue}{\frac{1}{x+3}}\)
- \(\color{blue}{\sqrt[3]{\frac{x+5}{2}}}\)
- \(\color{blue}{\frac{x}{10}}\)
- \(\color{blue}{x^2+8x+16}\)
- \(\color{blue}{\sqrt{\frac{x-2}{3}}}\), \(\color{blue}{-\sqrt{\frac{x-2}{3}}}\)
- \(\color{blue}{\frac{x}{22}}\)
Related to This Article
More math articles
- How to Multiply Polynomials Using Area Models
- 3rd Grade PEAKS Math Worksheets: FREE & Printable
- Using Number Lines to Add Two Integers with Different Signs
- The Ultimate Adults Math Refresher Course (+FREE Worksheets & Tests)
- Top 10 6th Grade SBAC Math Practice Questions
- 3rd Grade SBAC Math Practice Test Questions
- The Ultimate 6th Grade NYSTP Math Course (+FREE Worksheets)
- Full-Length 6th Grade PARCC Math Practice Test-Answers and Explanations
- 10 Most Common 4th Grade Georgia Milestones Assessment System Math Questions
- ALEKS Math Practice Test Questions
What people say about "How to Find Inverse of a Function? (+FREE Worksheet!) - Effortless Math: We Help Students Learn to LOVE Mathematics"?
No one replied yet.