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[[Category:problem solving]]
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[[Category:ECE301]]
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[[Category:ECE]]
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[[Category:Fourier transform]]
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[[Category:signals and systems]]
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== Example of Computation of Fourier transform of a CT SIGNAL ==
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A [[CT_Fourier_transform_practice_problems_list|practice problem on CT Fourier transform]]
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----
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<math>\ x(t) = e^{-2|t|}cos(8t)</math>
 
<math>\ x(t) = e^{-2|t|}cos(8t)</math>
  
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<pre> 4*(68+w^2)/(68+w^2-16*w)/(68+w^2+16*w) <\pre>
 
<pre> 4*(68+w^2)/(68+w^2-16*w)/(68+w^2+16*w) <\pre>
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----
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[[CT_Fourier_transform_practice_problems_list|Back to Practice Problems on CT Fourier transform]]

Revision as of 11:32, 16 September 2013

Example of Computation of Fourier transform of a CT SIGNAL

A practice problem on CT Fourier transform


$ \ x(t) = e^{-2|t|}cos(8t) $

$ X(\omega) = \int_{-\infty}^{\infty} x(t) e^{-j\omega t} dt \! $

$ = \int_{-\infty}^{\infty} e^{-2|t|}cos(8t) e^{-j\omega t} dt \! $

$ = \int_{-\infty}^{0} e^{2|t|}cos(8t) e^{-j\omega t} dt \! + \int_{0}^{\infty} e^{-2|t|}cos(8t) e^{-j\omega t} dt \! $


after quite a bit of math I get the answer to be


$ \frac{1}{2}(\frac{1}{2 + j8 - jw} + \frac{1}{2 -j8 -jw} + \frac{1}{2 - j8 - jw} \frac{1}{2 + j8 + jw}) $


I'm not sure if I'm right though because when I checked it in matlab the answer I got was

 4*(68+w^2)/(68+w^2-16*w)/(68+w^2+16*w) <\pre>

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[[CT_Fourier_transform_practice_problems_list|Back to Practice Problems on CT Fourier transform]]

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