Until now, we have addressed the question, "Given `f(x)`, what can we know about `f'(x)`?"
But now we will reverse it.
	Given the graph of `f'(x)` can we deduce what `f(x)` looks like?
     
You are given the graph of `f'(x)`, and your task is to reconstruct the graph of `f(x)`.
Once you can do this well, you are ready for 
the first derivative test.