An inverse function reverses a previous function.
So if f(x) is a function, we write its inverse as f-1(x).
There are three steps to follow when 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 now.
e.g. 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
In this activity, we will find the inverse of functions using the method shown above of finding an alternative subject of the function.