Hello everyone,

I am seeking a way to compute the sine-cosine form Fourier series of a 2π periodic function on [-π,π], using WolframAlfa. I found a similar topic : https://math.stackexchange.com/questions/3066381/how-can-i-compute-a-fourier-series-with-wolfram-alpha

But no concrete response has been posted yet I thought about computing the an and bn coefficients. After some researches I though the response could be the combination of :

FourierCosCoefficient and FourierSinCoefficient. But it does not seems to allow to change interval function. Looking deeply I found :

NFourierTrigSeries

but it does not seem to be able on WolframAlfa web compute tool.

Could someone explain to me the point I am missing for theses two options ? Thanks by advance