What is an inverse function?

An inverse function reverses the effect of the original function.

If f(x) turns x into y, then f⁻¹(x) turns y back into x.

How to find an inverse

1. Replace f(x) with y

2. Swap x and y

3. Solve for y

4. Replace y with f⁻¹(x)

Example

f(x) = x + 3

y = x + 3
Swap: x = y + 3
Solve: y = x − 3

f⁻¹(x) = x − 3