| Line 21: | Line 21: | ||
===Answer 1=== | ===Answer 1=== | ||
<math> X(z) =\frac{1}{\frac{3z}{z} - z} </math> | <math> X(z) =\frac{1}{\frac{3z}{z} - z} </math> | ||
| − | + | <math> =\frac{-1}{z} \frac{1}{1-\frac{3}{z}} </math> | |
<math> =\frac{-1}{z} \sum_{n=0}^{+\infty} (\frac{3}{z})^n </math> | <math> =\frac{-1}{z} \sum_{n=0}^{+\infty} (\frac{3}{z})^n </math> | ||
<math> =\sum_{n=0}^{+\infty} (-z^{-1}) (3z^{-1})^n </math> | <math> =\sum_{n=0}^{+\infty} (-z^{-1}) (3z^{-1})^n </math> | ||
Revision as of 13:58, 18 September 2013
Contents
Practice Question, ECE438 Fall 2013, Prof. Boutin
On computing the inverse z-transform of a discrete-time signal.
Compute the inverse z-transform of
$ X(z) =\frac{1}{3-z}, \quad \text{ROC} \quad |z|>3 $.
(Write enough intermediate steps to fully justify your answer.)
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
$ X(z) =\frac{1}{\frac{3z}{z} - z} $ $ =\frac{-1}{z} \frac{1}{1-\frac{3}{z}} $ $ =\frac{-1}{z} \sum_{n=0}^{+\infty} (\frac{3}{z})^n $ $ =\sum_{n=0}^{+\infty} (-z^{-1}) (3z^{-1})^n $
NOTE: $ (3z^{-1})^n = (3^n) (z^{-n}) (-z^{-1}) $
Answer 2
Write it here.
Answer 3
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Answer 4
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