(Power)
Line 4: Line 4:
 
</font>
 
</font>
  
== Power ==
+
==Energy==
<font size="4">
+
We will find the energy in one cycle of the cosine waveform.
<math>P = \int_{t_1}^{t_2} \! |y(t)|^2\ dt</math>
+
  
 +
<math>E=\int_0^{2\pi}{|cos(t)|^2dt}</math>
  
<math>P = \int_0^2 \! |e^2t\ dt</math>
 
  
 +
<math>=\frac{1}{2}\int_0^{2\pi}(1+cos(2t))dt</math>
  
<math>P = \int_0^2 \! exp(2t) dt</math>      (since exp(t) cannot be negative,take off the absolute value sign)
 
  
 +
<math>=\frac{1}{2}(t+\frac{1}{2}sin(2t))|_{t=0}^{t=2\pi}</math>
  
<math>P = {1\over 2} ( exp(2t) )\mid_0^{2}</math>
 
  
 +
<math>=\frac{1}{2}(2\pi+0-0-0)</math>
  
<math>P = {1\over 2}(exp(4) - 1)}</math>
+
 
</font>
+
<math>=\pi</math>

Revision as of 15:34, 3 September 2008

Signal

$ y(t)=exp(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 $

Alumni Liaison

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

Dr. Paul Garrett