Question

how to calculate the period of a fourier series?

Answer 1

Fourier series doesn't have any specific time period kind of thing, it is not a signal. it's the representation of periodic signals in terms of trigonometry functions or exponential functions. so you can have time period for signals not for Fourier series. For signals you calculate time period like follows, if signals is sin (At) then the time period is (2*pi)/A here 'A' is a integer or multiples of pi.