Question

If f(x) and f -1 (x) are inverse functions of each other and f(x) = 2x+5, what is f -1 (8)?

Answer 1

Answer: 3/2

Explanation:

The first one: y=2x+5

X=2y+5.Then solve for y after switching x and y

X-5=2y, X-5/2=y

Since F-1= X-5/ 2, we plug the value of X in

8-5/2, so it should be 3/2