Function

$ \,y = cos(x) $

Signal Energy

$ \,Energy = \int_0^{2\pi}{|cos(x)|^2dx} $

$ \, = \int_0^{2\pi}{|\frac{1+cos(2x)}{2}|dx} $
$ \, = \frac{1}{2}\int_0^{2\pi}{(1 + cos(2x))dx} $
$ \, = \frac{1}{2}(x + \frac{1}{2}sin(2x))|_0^{2/pi} $
$ \, = \frac{1}{2}(2\pi + 0 - 0 - 0) $
$ \, = \pi $

Signal Power

$ \, Power = \frac{1}{2\pi - 0}\int_0^{2\pi}{|cos(x)|^2dx} $

computation of the integral is the same as shown in the section above

$ \, = \frac{1}{2\pi}\frac{1}{2}(2\pi + 0 - 0 - 0) $
$ \, = \frac{1}{2} $

Alumni Liaison

Basic linear algebra uncovers and clarifies very important geometry and algebra.

Dr. Paul Garrett