Question

The value of the probability density function of random variable is

(a) Positive function

(b) Negative function

(c) Zero

(d) One

The question was posed to me in quiz.

Question is from Random Signals in section Signals and Spectra of Digital Communications

Answer 1

Right answer is (a) Positive function

To elaborate: The probability density function is always greater than 0. It is a non negative function with the area of 1.