Question Number 33311 by abdo imad last updated on 14/Apr/18
$${let}\:\:{f}\left({x}\right)\:=\mid{sinx}\mid\:\:\left(\mathrm{2}\pi\:{periodic}\:{even}\right) \\ $$$${developp}\:{f}\:{at}\:{fourier}\:{serie} \\ $$
let-f-x-sinx-2pi-periodic-even-developp-f-at-fourier-serie-