Question

Which function is the inverse of f(x) = –5x – 4?

Answer 1

f^(-1)(x) = \frac{-1}{5} (x+4)

Explanation:

Given is a function

`f(x) = -5x-4\\`

To find its inverse.

We must check whether f is one to one or onto first

If -5x1-4 = -5x2-4 we get x1=x2

Hence f is one to one

Also for every f(x) we can find a x so f is onto.

So inverse exists

Let

`y=-5x-4\\-5x=y+4\\x=(-1)/(5) (y+4)`

Replace x by f inverse and y by x

`f^(-1)(x) = (-1)/(5) (x+4)`