An inverse function reverses another function. If f(x) is a function, we write its inverse as f-1(x).
There are three steps to finding an inverse function:
Step 1. Change f(x)= into y=.
Step 2. Swap x and y.
Step 3. Make y the subject.
Let's have a look at an example:
Find the inverse of f(x) = 3x + 4
Step 1. y= 3x + 4
Step 2. x = 3y + 4
Step 3. x - 4 = 3y
(x - 4)/3 = y
So f-1(x) = (x - 4)/3.