c) If we define h = max, h, and let S(x) be the natural spline inter- polating f(x) at a;, i = 0, 1, . ...n, whre f(x) has a continuous second derivative, then 1 - max If(x) - S(x)| S h[hE(f)]. E(f) = (f" (t ) ) 2 dt 2 - max If'(x) - S'(x)I S [hE()]