Question

Please help! functions operations.

Answer 1

Answer:

3

Step-by-step explanation:

Use the property:

$f^{-1}(f(x))=x$

This implies that;

$f^{-1}(f(3))=3$

The correct choice is the first option.

Or see it in details below:

Given

$f(x)=9x+1$

substitute x=3, to obtain;

$f(3)=9(3)+1=28$

Let $y=9x+1$

Interchange x and y.

$x=9y+1$

Solve for y.

$x-1=9y$

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

This implies that;

$f^{-1}(x)=\frac{x-1}{9}$

$f^{-1}(f(3))=f^{-1}(28)$

$f^{-1}(28)=\frac{28-1}{9}$

$f^{-1}(28)=\frac{27}{9}=3$

Answer 2

The Answer is A. 3. :D