Question

Whats the answer and how do i get the answer myself

Answer 1

`f^(-1) (x) =  (x)/(3)  - 3`

Explanation:

Let here the given function f(x) = y

or,
`x= f^(-1) (y)`

⇒ y = 3x+ 9

Now, solving for x, we get

3x+ 9 = y ⇒ 3x = y - 9

or,
`x = (y-9)/(3) = (y)/(3)  - (9)/(3)`

⇒
`x = ( (y)/(3))  - 3`

Now, substituting x and y

Hence,
`f^(-1) (x) =  (x)/(3)  - 3`