If [tex]$f(x)=\frac{1}{9} x-2$[/tex], what is [tex]$f^{-1}(x)$[/tex]?

A. [tex]$f^{-1}(x)=9 x+18$[/tex]
B. [tex]$f^{-1}(x)=\frac{1}{9} x+2$[/tex]
C. [tex][tex]$f^{-1}(x)=9 x+2$[/tex][/tex]
D. [tex]$f^{-1}(x)=-2 x+\frac{1}{9}$[/tex]



Answer :

To find the inverse of the function [tex]\( f(x) = \frac{1}{9}x - 2 \)[/tex], follow these steps:

1. Express [tex]\( f(x) \)[/tex] as an equation with [tex]\( y \)[/tex]:
[tex]\[ y = \frac{1}{9}x - 2 \][/tex]

2. Swap [tex]\( x \)[/tex] and [tex]\( y \)[/tex] to solve for the inverse function:
[tex]\[ x = \frac{1}{9}y - 2 \][/tex]

3. Solve for [tex]\( y \)[/tex]:
[tex]\[ x + 2 = \frac{1}{9}y \][/tex]

4. Multiply both sides by 9 to isolate [tex]\( y \)[/tex]:
[tex]\[ 9(x + 2) = y \][/tex]

5. Simplify the equation:
[tex]\[ y = 9x + 18 \][/tex]

So, the inverse function is:
[tex]\[ f^{-1}(x) = 9x + 18 \][/tex]

Therefore, the correct answer is:
[tex]\[ f^{-1}(x) = 9x + 18 \][/tex]