(System Response)
(System Response)
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       = Response of <math>\frac{e^{2jt}}{2}\,</math> + Response of <math>\frac{e^{-2jt}}{2}\,</math>
 
       = Response of <math>\frac{e^{2jt}}{2}\,</math> + Response of <math>\frac{e^{-2jt}}{2}\,</math>
  
       <math>=\frac{te^{2jt}+te^{-2jt}}{2}\,</math> (since the integral is linear operation,so we can do addition and division by constant)
+
       <math>=\frac{te^{2jt}+te^{-2jt}}{2}\,</math> (since the integra, which is actually used in convolution, is linear operation,so we can do addition and division by constant)
  
 
       <math>=t\frac{e^{2jt}+e^{-2jt}}{2}\,</math>
 
       <math>=t\frac{e^{2jt}+e^{-2jt}}{2}\,</math>
  
 
       <math>=t\cos(2t)\,</math>
 
       <math>=t\cos(2t)\,</math>

Revision as of 08:25, 18 September 2008

System Response

Based on the Euler Formula, $ \cos(2t)\,= \frac{e^{2jt}+e^{-2jt}}{2}\, $.

We already had the response of $ e^{2jt}\, $ is $ te^{-2jt}\, $ and the response of $ e^{-2jt}\, $ is $ te^{2jt}\, $.

Since the system is a LTI system, we have

Output = Response of $ \frac{e^{2jt}+e^{-2jt}}{2}\, $

      = Response of $ \frac{e^{2jt}}{2}\, $ + Response of $ \frac{e^{-2jt}}{2}\, $
     $ =\frac{te^{2jt}+te^{-2jt}}{2}\, $ (since the integra, which is actually used in convolution, is linear operation,so we can do addition and division by constant)
     $ =t\frac{e^{2jt}+e^{-2jt}}{2}\, $
     $ =t\cos(2t)\, $

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