Question

1. determine if the functions are inverse functions

Answer 1

Answer:

Question 1

The function $f(x) = x + 6$ is one-to-one, so it does have an inverse.

The inverse of +6 is -6, so $f^{-1}(x)=x-6$

Therefore, g(x) is the inverse of f(x).

Question 2

The function $f(x) = -3x -9$ is one-to-one, so it does have an inverse.

To find the inverse, replace f(x) with y:

$\implies y = -3x -9$

Rearrange the equation to make x the subject:

$\implies y+9= -3x$

$\implies x=-\dfrac13(y+9)$

$\implies x=-\dfrac13y-3$

Replace x with $f^{-1}(x)$ and y with x:

$\implies f^{-1}(x)=-\dfrac13x-3$

Therefore, g(x) is the inverse of f(x).