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--[[User:Cmcmican|Cmcmican]] 20:52, 21 February 2011 (UTC)
 
--[[User:Cmcmican|Cmcmican]] 20:52, 21 February 2011 (UTC)
  
TA's comments: In the time shift property of the Fourier transform that you provided, it should be <math class="inline">e^{-j\omega t_0}</math> and not <math class="inline">e^{j\omega t_0}</math>. Another thing is that the transform of a cosine should yield only two deltas in the frequency domain.
+
:TA's comments: In the time shift property of the Fourier transform that you provided, it should be <math class="inline">e^{-j\omega t_0}</math> and not <math class="inline">e^{j\omega t_0}</math>. Another thing is that the transform of a cosine should yield only two deltas in the frequency domain.
  
 
=== Answer 2  ===
 
=== Answer 2  ===

Revision as of 08:59, 22 February 2011


Practice Question on Computing the Fourier Transform of a Continuous-time Signal

Compute the Fourier transform of the signal

$ x(t) = \cos (2 \pi t+\frac{\pi}{12} )\ $


Share your answers below

You will receive feedback from your instructor and TA directly on this page. Other students are welcome to comment/discuss/point out mistakes/ask questions too!


Answer 1

Use answer to previous practice problem and the time shifting property.

$ \mathfrak{F}\Bigg(s(t-t_0)\Bigg)=e^{j\omega t_0}\mathfrak{F}\Bigg(x(t)\Bigg) $

Therefore,

$ \chi(\omega)=e^{j\omega \frac{\pi}{12}}2\pi \delta(\omega-2\pi k) $

--Cmcmican 20:52, 21 February 2011 (UTC)

TA's comments: In the time shift property of the Fourier transform that you provided, it should be $ e^{-j\omega t_0} $ and not $ e^{j\omega t_0} $. Another thing is that the transform of a cosine should yield only two deltas in the frequency domain.

Answer 2

Write it here.

Answer 3

Write it here.


Back to ECE301 Spring 2011 Prof. Boutin

Alumni Liaison

Ph.D. 2007, working on developing cool imaging technologies for digital cameras, camera phones, and video surveillance cameras.

Buyue Zhang