I've been watching videos from this guy, http://www.youtube.com/watch?v=ikeIWcBoXUI , and I find them fairly useful as far as procedure, but in our classes we are told to convert everything to cos which he does not do. Further, his equations are are √2 times sin, but he leaves off the √2 during calculations. More specifically, 100√2 sin(bla) gives what he calls the RMS voltage of 100, ignoring the root and ignoring the fact that it's a sin. I believe that it works, I just don't know what he's doing.