3. (i) A function f satisfies the two conditions f = f (t) and f(t+ = f (t) for all t. Show that its Fourier coefficients satisfy ao = = a4 = (ii) A function f satisfies the two conditions its Fourier coefficients satisfy ao = al = 02 = = = O, b2 b4 = b6 -o,bl aud f(t+ * ) = f (t) for all t. Show that