Question

If f (x) = one-ninth x minus 2, what is f-1(x)

Answer 1

Answer:

$f^{-1}$(x) = 9x + 18

Step-by-step explanation:

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

y = $\frac{1}{9}$ x - 2 ( add 2 to both sides )

y + 2 = $\frac{1}{9}$ x

Multiply through by 9 to clear the fraction

9y + 18 = x

Change y back into terms of x

$f^{-1}$ (x) = 9x + 18

Answer 2

Answer:

f-1(x) = 9x + 18.

Step-by-step explanation:

Let y = 1/9 x - 2

1/9 x = y + 2

x = (y + 2) / 1/9

x=  9(y + 2)

x = 9y + 18

Now replace the x by the inverse f-1(x) and the y by x:

f-1(x) = 9x + 18.