After over an hour of pondering, I cannot seem to be able to figure out how to do this problem. I have taken pre-calculus and trigonometry and am in calculus 1 right now where we are "reviewing." Anyways, here is the problem, I was just looking for some help on how to solve it.

(The solution guide steps are right under it but I can't seem to figure out what's going on.)

Find the domain and range.

Thanks by the way.