I'm a bit stuck on these. A nudge in the right direction would be much appreciated.

I can't seem to figure out what to do with that sin(x) function. If I let

, I can get the whole thing into the form of the derivative of arctan(x), except for the sin(x).

The other one that's bugging me is:

No excuse here. I've tried quite a few different substitutions and algebraic manipulations without success. I can't shake the feeling that I'm over-looking something glaring with this problem. I think I found a method that would involve using partial fractions, but I was told that none of these problems required that method.