Ahahaha, funny. I'm doing sine and cosine waves in my math class right now. :3
Anyways, in regards to the DOOBSTEP, it was pretty freakin' sweet, as usual. Although I do agree with the others, some parts are a bit repetitive, like at 1:44 with that one noise. It was a tad annoying, but overall didn't really damage the overall awesomeness too much. Sweet tunes as always.