At some point, very early in your Calculus class, you should learn:
(f+ g)'= f'+ g'
(f- g)'= f'- g'
(fg)'= f'g+ fg'
You need the first three of those here.
Yeah, I know that. I even understand the proofs behind the elementary differentiation formulas. It's just that, when I initially looked at this problem, I was confused because of the notation used. We were studying the derivatives of inverse functions at the time, and then my techer threw this gem in there. Threw me for a loop.