# Math Help - Find the Inverse of the Function

1. ## Find the Inverse of the Function

Find the inverse of the function f(x) = mx + b, where m cannot equal 0.

2. Originally Posted by magentarita
Find the inverse of the function f(x) = mx + b, where m cannot equal 0.
Let $y=mx+b$

Rearrange to make $x$ the subject, so you will get:

$x = \frac{y-b}{m}$

This is your inverse. Remember to change it back to correct format, which is:

$f'(x) = \frac{x-b}{m}$

3. ## That easy???

I should have tried harder. The question is all too easy.

Thanks Air.

Rita

4. ## Rule of thumb

I always use a simple trick to remember inverse functions, especially with linear equations:

A function's slope times the inverse of that functions slope equals -1

5. ## rman144

Thanks for Rule of Thumb.