Question

If f(x)= -8x+4, then f^-1(x)=

Answer 1

`f^(-1)`(x) =
`(4-x)/(8)`

Explanation:

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

y = - 8x + 4 ( add 8x to both sides )

8x + y = 4 ( subtract y from both sides )

8x = 4 - y ( divide both sides by 8 )

x =
`(4-y)/(8)`

Change y back into terms of x

`f^(-1)`(x) =
`(4-x)/(8)`