Multiple choice

If S(f) is the power spectral density of a real, wide-sense, stationary random process, then which of the following relations is true?

  1. S(0) $\ge$ S(f)
  2. S(f) $\ge$ 0
  3. S(–f) = –S(f)

  4. $\int_{-\infty}^\infty S(f) \ df = 0$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Power spectral density is non-negative. Thus, it is always zero or greater than zero.