(Energy)
(Energy)
 
(12 intermediate revisions by the same user not shown)
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== Energy ==
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<font size="5">
+
<font size="3">
  
 
Consider the signal  
 
Consider the signal  
 
<math>x(t)=cos(t)</math> over the interval 0 to <math>4\pi</math>
 
<math>x(t)=cos(t)</math> over the interval 0 to <math>4\pi</math>
 +
== Average Power ==
  
  
 +
<math>Avg. Power = {1\over(t2-t1)}\int_{t_1}^{t_2}\!|x(t)|^2 dt</math>
  
<math>E = {1\over(t2-t1)}\int_{t_1}^{t_2}\!|x(t)|^2 dt</math>
 
  
 +
<math>Avg. Power = {1\over(4\pi-0)}\int_{0}^{4\pi}\!|cos(t)|^2 dt</math>
  
<math>E = {1\over(4\pi-0)}\int_{0}^{4\pi}\!|cos(t)|^2 dt</math>
 
  
 +
<math>Avg. Power = {1\over(4\pi)}{1\over2}\int_{0}^{4\pi}\!(1+cos(2t)) dt</math>
  
<math>E = {1\over(4\pi)}{1\over4}\int_{0}^{4\pi}\!(1+cos(2t)) dt</math>
 
  
 +
<math>Avg. Power = {1\over8\pi}(4\pi+{1\over2}sin(8\pi)) </math>
  
<math>E = {1\over\pi}(4\pi+{1\over2}sin(4\pi)) dt</math>
 
  
 
+
<math>Avg. Power = {1\over2}</math>
<math>E = {2}</math>
+
  
 
</font>
 
</font>
  
== Power ==
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== Energy ==
 
<font size="4">
 
<font size="4">
  
<math>f(t)=2cos(t)</math>
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<math>E = \int_{t_1}^{t_2}\!|x(t)|^2\ dt</math>
 
+
  
<math>P = \int_{t_1}^{t_2}\!|f(t)|^2\ dt</math>
 
  
  
 +
<math>E = \int_{0}^{4\pi}\!|cos(t)|^2\ dt</math>
  
<math>P = \int_{0}^{2\pi}\!|2cos(t)|^2\ dt</math>
 
  
 +
<math>E = {1\over2}\int_{0}^{4\pi}\!(1+cos(2t)) dt</math>
  
<math>P = (4){1\over2}\int_{0}^{2\pi}\!1+cos(2t) dt</math>
 
  
 +
<math>E = {1\over2}(4\pi+{1\over2}sin(8\pi))</math>
  
<math>P = (4){1\over2}(2\pi+{1\over2}sin(2*2\pi)</math>
 
  
 +
<math>E = 2\pi</math>
  
<math>P = 4\pi</math>
 
 
</font>
 
</font>

Latest revision as of 14:19, 5 September 2008

Consider the signal $ x(t)=cos(t) $ over the interval 0 to $ 4\pi $

Average Power

$ Avg. Power = {1\over(t2-t1)}\int_{t_1}^{t_2}\!|x(t)|^2 dt $


$ Avg. Power = {1\over(4\pi-0)}\int_{0}^{4\pi}\!|cos(t)|^2 dt $


$ Avg. Power = {1\over(4\pi)}{1\over2}\int_{0}^{4\pi}\!(1+cos(2t)) dt $


$ Avg. Power = {1\over8\pi}(4\pi+{1\over2}sin(8\pi)) $


$ Avg. Power = {1\over2} $

Energy

$ E = \int_{t_1}^{t_2}\!|x(t)|^2\ dt $


$ E = \int_{0}^{4\pi}\!|cos(t)|^2\ dt $


$ E = {1\over2}\int_{0}^{4\pi}\!(1+cos(2t)) dt $


$ E = {1\over2}(4\pi+{1\over2}sin(8\pi)) $


$ E = 2\pi $

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