Signal Analysis and transmission

Q6. Signum function sgn(f), for f>0, f=0 and f<0, has the values:

Options:

a) a) -1 to +1
b) b) +1, 0, -1 respectively
c) c) -∞ to + ∞
d) d) 0 always

Correct Answer: b) +1, 0, -1 respectively

Explanation :

The sgn(f) is a signum function that is defined in the frequency domain as
sgn(f) = 1, f> 0
= 0, f= 0
= -1, f< 0
Mathematically, the sign function or signum function is an odd mathematical function which extracts the sign of a real number and is often represented as sgn.