# Quick inverse question

## Homework Statement

Inverse of g(x) = x/3 -5

## The Attempt at a Solution

The inverse of the function

g(x) = x/3 -5
x= y/3 -5
x +5 = y/ 3
3x + 15 = y

Is this correct?

Or is it x+5 /3 ?

## Answers and Replies

Your original looks correct.

If you have a graphic calculator, graph them both, the inverse should be a 90* rotation from the original, since you essentially have the same function with swapped axis.

If you want to check to see if the inverse function you found is correct, all you need to do is form a composite function of the original function and its inverse. If the composite function of g(x) and g-1(x) is equal to x, then the inverse you found is correct.

$g[g^{-1}(x)]=(\frac{3x+15}{3})-5=(x+5)-5=x$

Yes, the inverse you found is correct.