Question

F(x)=3x-2 find f^-1(x) than find f^-1(13)

Answer 1

if X is -1 then sub and it will equal -5

Answer 2

see explanation

Explanation:

let y = f(x) and rearrange making x the subject, that is

y = 3x - 2 ( add 2 to both sides )

y + 2 = 3x ( divide both sides by 3 )

`(y+2)/(3)` = x

change y back into terms of x with x =
`f^(-1)` (x)

`f^(-1)` (x) =
`(x+2)/(3)`

To evaluate
`f^(-1)` (13) substitute x = 13 into
`f^(-1)` (x) , that is

`f^(-1)` (13) =
`(13+2)/(3)` =
`(15)/(3)` = 5