A friend of mine told me that for fourier series If the function is odd or even and have its reflection on x-achse after half the period (u(t+T/2)=-u(t)) then one of the coefficient is zero (no problem with this) and the other one is the definition of Fourier coefficient normally but multiplied by 8 and integrated till quarter of the period .
Is this true ?
I asked the question here because I am in holiday now and i don't have anyone other than the Internet to ask
Thanks in advance