You probably haven't seen these before, but they really do make ultra cool Calculus problems.  I've seen them in most texts.  They're really pretty easy if you look at them the right way.

First, let's look at what absolute values do:

| 3 | = 3

| 0 | = 0

| -5 | = 5
 

Absolute values leave positive numbers and zero alone...  and make negative numbers positive!

So, with graphs...  let's think about the y guys:

The y guys above the x axis are positive y's  ...  the y guys below the x axis are negative y's