Question

Which of the following is not Dirichlet’s condition for the Fourier series expansion?

(a) f(x) is periodic, single valued, finite

(b) f(x) has finite number of discontinuities in only one period

(c) f(x) has finite number of maxima and minima

(d) f(x) is a periodic, single valued, finite

This question was posed to me in my homework.

I'd like to ask this question from Fourier Series Expansions in chapter Fourier Series of Engineering Mathematics

Answer 1

The correct answer is (d) f(x) is a periodic, single valued, finite

Easiest explanation: Dirichlet’s condition for Fourier series expansion is f(x) should be periodic, single valued and finite; f(x) should have finite number of discontinuities in one period and f(x) should have finite number of maxima and minima in a period.