Question

If f(x) = 9x, which of the following is the inverse
of f(x)?
0 f-1(x) =x-9
•f-1(x) =x+9
0 f-1(x)=9x
O f1 (x) = 2

Answer 1

To find the inverse of the function \( f(x) = 9x \), we follow these steps:

1. Replace \( f(x) \) with \( y \):
\[
y = 9x
\]

2. Solve for \( x \) in terms of \( y \):
\[
x = \frac{y}{9}
\]

3. Now, swap \( x \) and \( y \) to find the inverse function:
\[
f^{-1}(x) = \frac{x}{9}
\]

Among the options you provided:

- \( f^{-1}(x) = x - 9 \)
- \( f^{-1}(x) = x + 9 \)
- \( f^{-1}(x) = 9x \)
- \( f^{-1}(x) = 2 \)

None of these options correctly describe the inverse function \( f^{-1}(x) = \frac{x}{9} \). Therefore, none of the options given are correct.