Unity+

Well, it dealt with the integral of cos^2x, since we were learning to use trig identities to solve integrals.(at least, I think that was the integral. I would have to check my notes again). The way it was proven was through taking the integral, and since another integral popped up, we solved for that integral, which would lead to the same integral that we were solving originally. We would then subtract that integral about the original one and it was solved.

I remember using such tricks before for integrals like that. It is okay as long as you are sure the integral is well defined. That would take you into measure theory, which is not a first year course.

well, the professor was teaching us it, so i dont know then.