Energy
$ E = \int_{t1}^{t2}{|x(t))|^2dt} $
Usint this result let us consider an example,
$ = \int_{0}^{2 \pi}{|cos(t)|^2dt} $
$ =\int_{0}^{2\pi}\frac(1+cos(2t)}{2}dt $ $ =\frac{2\pi}{2}+\frac[1}{4}sin(4\pi) $ $ =\{1\pi} $
Power
$ P = \frac{1}{2 \pi - 0} \int_{0}^{2 \pi}{|cos(t)|^2dt} $
$ = \frac{1}{2 \pi} \int_{0}^{2 \pi}\frac{[1 + cos(2t)]}{2}dt $
$ =\frac{1}{2} $
