I'm going to give my even answers so far just to compare and see if everyone else is getting the same. Some are a little weird in my opinion. I used a calculator on a few too. -By the way, go here and make sure your preferences are set right so it makes these easier to read.
$ 38: \pi $
$ 48: x - \arctan{x} + c $
$ 50: -22.578 $
$ 56: \frac{\pi}{4} + \ln{2} $
$ 84 a) = -\cos(\theta)+\frac{1}{3}\cos^3(\theta)+c $
$ 84b) = -\cos(\theta)+\frac{2}{3}\cos^3(\theta)-\frac{1}{5}\cos^5(\theta)+c $
---Gary Brizendine II 14:51, 7 October 2008 (UTC)