(→Energy) |
(→Power) |
||
Line 31: | Line 31: | ||
− | <math>P = \int_{ | + | <math>P = \int_{0}^{2\pi}\!|2cos(t)|^2\ dt</math> |
+ | <math>P = (4)\int_{0}^{2\pi}\!1+cos(2t) dt</math> | ||
+ | |||
+ | <math>P = (4)(2\pi+{1\over2}sin(2*2\pi)</math> | ||
+ | |||
+ | |||
+ | <math>P = 8\pi</math> | ||
</font> | </font> |
Revision as of 15:03, 4 September 2008
Energy
$ f(t)=2cos(t) $
$ E = {1\over(t2-t1)}\int_{t_1}^{t_2}\!|f(t)|^2 dt $
$ E = {1\over(2\pi-0)}\int_{0}^{2\pi}\!|2cos(t)|^2 dt $
$ E = {1\over(2\pi-0)}{1\over2}(4)\int_{0}^{2\pi}\!(1+cos(2t)) dt $
$ E = {1\over\pi}(2\pi+{1\over2}sin(2*2\pi)) dt $
$ E = {2} $
Power
$ f(t)=2cos(t) $
$ P = \int_{t_1}^{t_2}\!|f(t)|^2\ dt $
$ P = \int_{0}^{2\pi}\!|2cos(t)|^2\ dt $
$ P = (4)\int_{0}^{2\pi}\!1+cos(2t) dt $
$ P = (4)(2\pi+{1\over2}sin(2*2\pi) $
$ P = 8\pi $