Consider the system with following input-output relation y [n] = (1 + ...
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 + ...
**Input-Output Relationship**
The given system has the following input-output relationship:
y [n] = (1 (-1)n) x [n]
where x[n] is the input and y[n] is the output.
**Invertibility**
A system is said to be invertible if different inputs produce different outputs. In other words, if two different inputs x1[n] and x2[n] result in the same output y[n], then the system is not invertible.
Let's consider two different inputs: x1[n] = 1 and x2[n] = (-1)n.
For x1[n] = 1,
y1[n] = (1 (-1)n) * 1
= 1
For x2[n] = (-1)n,
y2[n] = (1 (-1)n) * (-1)n
= -(-1)n
= (-1)n+1
For n even, y2[n] = (-1)n+1 = -1
For n odd, y2[n] = (-1)n+1 = 1
Therefore, for n even, y1[n] = y2[n], and for n odd, y1[n] = -y2[n]. This implies that the system is not invertible, as two different inputs x1[n] = 1 and x2[n] = (-1)n result in the same output for n even.
**Time Invariance**
A system is said to be time-invariant if a time shift in the input results in a corresponding time shift in the output. In other words, if x[n] produces y[n], then x[n - k] should produce y[n - k], where k is a constant.
Let's consider the input x1[n] = 1.
For x1[n] = 1,
y1[n] = (1 (-1)n) * 1
= 1
Now, let's consider the input x2[n] = 1, delayed by k samples.
For x2[n - k] = 1,
y2[n - k] = (1 (-1)n) * 1
= 1
Therefore, for both x1[n] = 1 and x2[n] = 1 delayed by k samples, the output y[n] remains the same. Thus, the system is time-invariant.
**Conclusion**
Based on the analysis, the given system is non-invertible and time-invariant. Therefore, the correct answer is option D: non-invertible and time varying.