(Question 6a)
(Question 6a)
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<math> X_k[n]=Y_k[n] \,</math>
 
<math> X_k[n]=Y_k[n] \,</math>
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where  
 
where  
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Consider the value of the system at when time = 0s
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Consider the input and output of the system when k = 1
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<math> X_1[n]=\delta[n-1]\,</math>   
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and
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<math> Y_1[n]=\delta[n-2] \,</math>
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If I time shift the input by <math> n_0\,</math> , then run it through the system I obtain:
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Under this assumption the following system cannot possibly be time invariant because of the <math>(k+1)^2</math> term.
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If I run it through the system, then time shift the output by <math> n_0\,</math> I obtain:

Revision as of 08:33, 11 September 2008

Question 6a

I'm assuming $ n\, $ is the variable I will be applying the time shift to. I looked at some other peoples work and although they all thought $ k\, $ was the time variable, I think $ k\, $ is just the time step moving the function forward relative to some time position $ n\, $. In other words , $ k=2\, $ doesn't mean time = 2 sec, it just means 2 time steps ahead of time $ n\, $. Another reason I chose $ n\, $ to be the time variable is because when you discussed the sifting property in class you sifted by $ n_0\, $, not $ k\, $.


$ X_k[n]=Y_k[n] \, $


where

$ X_k[n]=\delta[n-k]\, $


and

$ Y_k[n]=(k+1)^2 \delta[n-(k+1)] \, $


Consider the input and output of the system when k = 1

$ X_1[n]=\delta[n-1]\, $


and

$ Y_1[n]=\delta[n-2] \, $

If I time shift the input by $ n_0\, $ , then run it through the system I obtain:


If I run it through the system, then time shift the output by $ n_0\, $ I obtain:

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