Question

Find the inverse Z – Transform of \(log \frac{z}{z+1}\).

(a) \(\frac{(-1)^n}{n} \)

(b) \(\frac{(-1)^{n+1}}{n} \)

(c) \(\frac{1}{n} \)

(d) \(\frac{(-1)^n}{n+1} \)

The question was asked in a job interview.

My question is based upon Linear Difference Equations and Z in chapter Fourier Integral, Fourier Transforms and Integral Transforms of Engineering Mathematics

Answer 1

The correct choice is (a) \(\frac{(-1)^n}{n} \)

Best explanation: First, substitute z as \((\frac{1}{y})\) and then expand the got result. This is in the format of the Z-Transform expansion. Thus we get the required results.