Question

Find the final value of the function F(s) given by \(\frac{(s-1)}{s(s^2-1)}\).

(a) 1

(b) 0

(c) -1

(d) ∞

This question was posed to me during an interview.

The above asked question is from Properties of the Laplace Transform in division Laplace Transform and System Design of Signals and Systems

Answer 1

Correct option is (a) 1

To explain: Given F(s) = \(\frac{(s-1)}{s(s^2-1)}\)

The final value is f(∞)=lims→0⁡ sF(s)

= lims→0⁡ s \(\frac{(s-1)}{s(s^2-1)} = lim_{s→0} \frac{1}{s+1} = 1\).