This one looks pretty easy, but I keep getting the wrong answer. Here's the problem.
$ \int_{0}^{2Pi}\sqrt{\frac{1-\cos{x}}{2}}dx $
Obviously, $ \frac{1-\cos{x}}{2} = \sin^2{\frac{x}{2}} $
So, the integral should then look like:
$ \int_{0}^{2Pi}\sin{\frac{x}{2}}dx $
