Find the Fourier series expansion of the periodic function f(x) in the given interval, where the period is T.
f(x) = 0, for 0 < x < T
f(x) = Σ[3((-1)^n+1)/n]sin(nx), for 0 < x < T
f(x) = Σ[3((-1)^n+1)/n] + lsin(nx), for 0 < x < T
f(x) = Σ[2(3((-1)^n+1)/n)sin(nx)], for 0 < x < T
f(x) = 1 + Σ[2(3((-1)^n+1)/n) + lcos(nx)], for 0 < x < T, n=1