F(x) = x sin(x), a = 0, n = 4, −0.9 ≤ x ≤ 0.9 (a) Approximate f by a Taylor polynomial with degree n at the number a. T4(x) = x2−16x4 (b) Use Taylor's Inequality to estimate the accuracy of the approximation f(x) ≈ Tn(x) when x lies in the given interval. (Round M up to the nearest integer. Round your answer to four decimal places.) |R4(x)| ≤