1-6 A function f is given on the interval [-π, π] 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 f and the partial sums S2, S4, and S6 of the Fourier series. x<0 -1 if 0x < πT [1 if 1. f(x) = 0 if x < 0 2. f(x) = if 0 < x <π 3. f(x) = x 4. f(x) = x²