(New page: Consider the signal <math>x(t)=cos(t)</math>. ==Energy== We will find the energy in one cycle of the cosine waveform. <math>E=\int_0^{2\pi}{|cos(t)|^2dt}</math> <math>=\frac{1}{2}\int_...)
 
(Energy)
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<math>=\pi</math>
 
<math>=\pi</math>
 
 
  
 
==Energy==
 
==Energy==

Revision as of 19:26, 2 September 2008

Consider the signal $ x(t)=cos(t) $.

Energy

We will find the energy in one cycle of the cosine waveform.

$ E=\int_0^{2\pi}{|cos(t)|^2dt} $


$ =\frac{1}{2}\int_0^{2\pi}(1+cos(2t))dt $


$ =\frac{1}{2}(t+\frac{1}{2}sin(2t))|_{t=0}^{t=2\pi} $


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


$ =\pi $

Energy

We will find the average power in one cycle of the cosine waveform.

$ E=\frac{1}{2\pi-0}\int_0^{2\pi}{|cos(t)|^2dt} $


$ =\frac{1}{2\pi-0}\frac{1}{2}\int_0^{2\pi}(1+cos(2t))dt $


$ =\frac{1}{4\pi}(t+\frac{1}{2}sin(2t))|_{t=0}^{t=2\pi} $


$ =\frac{1}{4\pi}(2\pi+0-0-0) $


$ =\frac{1}{2} $

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