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| − | <math>=\frac{1}{4\pi}( | + | <math>=\frac{1}{4\pi}(\pi+0-(0-\pi))</math> |
<math>=\frac{1}{2}</math> | <math>=\frac{1}{2}</math> | ||
Revision as of 05:42, 5 September 2008
cos(t-2)
Energy
$ u = (t-\pi) $
$ E=\int_0^{2\pi}{|cos(u)|^2du} $
$ E=\frac{1}{2}\int_0^{2\pi}(1+cos(2(u)))du $
$ E=\frac{1}{2}((u+\frac{1}{2}sin(2(u)))|_{u=-\pi}^{u=2\pi-\pi} $
$ E=\frac{1}{2}(\pi + 0 -(-\pi - 0)) $
$ E=\pi $
Power
$ E=\frac{1}{2\pi-0}\int_0^{2\pi}{|cos(u)|^2du} $
$ =\frac{1}{2\pi-0} *{\frac{1}{2}}\int_0^{2\pi}(1+cos(2u))du $
$ =\frac{1}{4\pi}((u)+\frac{1}{2}sin(2u))|_{u=-\pi}^{u=2\pi-\pi} $
$ =\frac{1}{4\pi}(\pi+0-(0-\pi)) $
$ =\frac{1}{2} $
