Question

If f(x) = 1/9x -2, what is f-1(x)

Answer 1

Answer:

$f^{-1}(x)$ will be equal to 9y+18

Step-by-step explanation:

We have given $f(x)=\frac{1}{9}x-2$

Now let $f(x)=y$

So $y=\frac{1}{9}x-2$

We have to find $f^{-1}(x)$ , means value of x in terms of y

So $y=\frac{1}{9}x-2$

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

$x=9y+18$

So $f^{-1}(x)$ will be equal to 9y+18

Answer 2

Please, try typing

  -1
f     (x)  to indicate "inverse function."

Type   f(x) = 1/9x -2    as   f(x) = (1/9)x -2

1) replace f(x) with y:          y =  (1/9)x -2
2)  Interchange x and y:      x = (1/9)y - 2
3)  Solve for y:                     9x = y - 18, or y = 9x + 18
4)  replace y with 

  -1
f     (x)   

Then

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