Consider the system with following input-output relation y[n] =(1 + ( ...
Given y [ n ] = (1 + ( -1)n ) x [ n ]
For time invariance
Since Since (1) is not equal to (2) system is time variant
For inverse system
For each unique x [n ] , there should be unique y [n ]
If x[n] = δ[n-1]
y[n] = [ 1 + (-1)n ] δ[n-1]
⇒ y[1] = 0
if x[n] = 2δ[n-1]
y[n] = [ 1+(-1)n ] 2δ (n-1)
y(1) = 0
For two different inputs we have same output. Thus one to one mapping is not possible. Hence the systems is non invertible
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Consider the system with following input-output relation y[n] =(1 + ( ...
Answer:
Introduction
In this question, we are given the input-output relation of a system, and we need to determine whether the system is invertible and time invariant, invertible and time varying, non-invertible and time invariant, or non-invertible and time varying.
Input-Output Relation
The given input-output relation is:
y[n] = (1 - (-1)^n) * x[n]
Time Invariance
A system is time invariant if a time shift in the input signal results in a corresponding time shift in the output signal. Let's check if the given system is time invariant.
Let's consider two time-shifted input signals: x1[n] = x[n - k] and x2[n] = x[n - k + 1], where k is a positive integer.
The output corresponding to x1[n] is:
y1[n] = (1 - (-1)^n) * x1[n]
= (1 - (-1)^n) * x[n - k]
The output corresponding to x2[n] is:
y2[n] = (1 - (-1)^n) * x2[n]
= (1 - (-1)^n) * x[n - k + 1]
If the system is time invariant, then y1[n] should be equal to y2[n]. Let's check this condition.
Comparing y1[n] and y2[n]:
y1[n] = (1 - (-1)^n) * x[n - k]
y2[n] = (1 - (-1)^n) * x[n - k + 1]
Since k is a positive integer, x[n - k] and x[n - k + 1] are two consecutive samples of the input signal. In the given relation, we see that the output depends on whether n is even or odd, which means it depends on the specific sample of the input signal. Therefore, the system is time varying.
Invertibility
A system is invertible if different input signals produce different output signals. Let's check if the given system is invertible.
Consider two different input signals: x1[n] and x2[n].
The output corresponding to x1[n] is:
y1[n] = (1 - (-1)^n) * x1[n]
The output corresponding to x2[n] is:
y2[n] = (1 - (-1)^n) * x2[n]
If the system is invertible, then y1[n] should be different from y2[n] for different input signals. However, in the given relation, we see that the output depends on whether n is even or odd, which means it depends on the specific sample of the input signal. Therefore, the system is non-invertible.
Conclusion
Based on the analysis, we can conclude that the given system is non-invertible and time varying. Therefore, the correct answer is option D.
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