Energy of cos(2t) from t= 0 to 2
$ E = \int_{t2}^{t1}{|(f(t)|^2}dt $
$ E = 2cos(2(2)) $
$ E = 2cos(4) $
$ E = 2 $
Power of cos(2t)
$ P = \frac{1}{t2-t1}\int_{t2}^{t1}{|f(t)|^2}dt $
