Question 4 (Taylor series and truncation error) (10 points) Use Taylor series expansion of f(x) = cos(Tex/2) to estimate the value of f(1/2) to an error of at least 10-3. Question 5 (Finite difference approximations of derivatives) (15 points) Use forward, backward, and centered difference approximations to estimate the first derivative of f(x) = (et 1)/x at x = 2 using the step size h = 0.5. Compare the true percent relative error of each approximation