![](images/Problem_Down.jpg) ![](images/Solution_Up.jpg) |
![](images/b.gif) |
Solution 6 |
(a) δ[n + 5]
The Z-transform of δ[n] is 1, now the Z-transform of δ[n + 5] will be Z5 , by the property that if Z-transform of x[n] is X(Z) then the Z-transform of x[n-m] will be
. . The region of convergence in this case is the entire z plane except
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(b) δ[n - 5]
The Z-transform of δ[n] is 1, now the Z-transform of δ[n - 5] will be Z-5 , by the property that if Z-transform of x[n] is X(Z) then the Z-transform of x[n-m] will be . The region of convergence in this case is the entire z plane except
![](images/mod4_s1/image046.gif) |
(c) (-1)nu[n]
has the Z-transform
hence the sequence (-1)nu[n] will have the Z-transform
with the region of convergence
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(d)
hence from combining the shifting property and the above used
property we can get the Z-transform to be as follows
. The region of convergence will be note that infinity is not in the ROC
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(e)
If the X(Z) is the Z-transform of x[n] then we shall use the following properties to solve the above problem.
1. Z-transform of x[n-m] will be . The ROC is all Z except 0( if m > 0) or infinity(if m < 0 )
2.
has the Z-transform The ROC is
Hence the Z-Transform will be, (in k, we now shift it by m = -1)
Hence the final transform will be with region of convergence . |
(f)
, hence now the
Z-transform using a procedure similar to the one above will be![](images/mod4_s1/image082.gif)
with a region of convergence note here 0 is not in the ROC |
(g)
, hence the Z-transform will be
, with region of convergence
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(h)
By the shifting property and the property
has the Z-transform
,
we get the Z-transform to be with the region of convergence
![](images/mod4_s1/image084.gif) |