1-6 III A function f is given on the interval [-π, 7] and fis periodic with period 2π. (a) Find the Fourier coefficients of f. (b) Find the Fourier series of f. For what values of x is f(x) equal to its Fourier series? (c) Graph and the partial sums S2, S4, and S6 of the Fourier series. - 0 if x < 0 2. f(x) = X if 0xπ