2) Inverse functions
An inverse function is a second function which undoes the work of the ﬁrst one. In this unit we describe two methods for ﬁnding inverse functions, and we also explain that the domain of a function may need to be restricted before an inverse function can exist.
If , find
First, rearrange in terms of:
Remember to change y back to x when you’re writing your answer:
Find the inverse of .
To ﬁnd the inverse of f(x), we swap the x and y values which represent the inputs and outputs. To ﬁnd the inverse function we now make y the subject.
Now use the same method to solve this question.