HW 3 Question 1 - Rhea

1 a)

$ x_(t) \,\!= \cos(\frac{\pi}{2})rect(\frac{t}{2}) $

Based on the Prof Alen's note page 179

$ x_(f) \,\!= \frac{1}{2}( \delta (f - \frac{1}{4}) + \delta (f + \frac{1}{4}))sinc(t/2) $

• Would you know how to compute this FT without a table if asked? --Mboutin 10:45, 9 February 2009 (UTC)

b)

$ x_(t) \,\!= repT[x0_(t)] = \frac {1}{T} \sum_{k} cos(\frac{\pi}{2})rect(\frac{t}{4}) $

Based on the Prof Alen's note page 184

$ x_(f) \,\!= \frac{1}{T}\sum_{k} ( \delta (f - \frac{1}{4}) + \delta (f + \frac{1}{4}))( \delta (f - \frac{k}{4})) $

• Can you write your answer using a comb operator? --Mboutin 10:45, 9 February 2009 (UTC)
• How did you get to that answer? Please add some intermediate steps. --Mboutin 10:50, 9 February 2009 (UTC)