Gauss interpolation. (a) Find the Chebyshev interpolation polynomial with n = 4 to approximate f(x) = : 4 x cos(x) on interval (-pih/4, phi/2]. Compute the error bound! (b) Find the Legendre interpolation polynomial with n = 4 on the same problem. Compute the error bound and compare it to that of the Chebyshev, (which one is better?) Hint: Use MATLAB to find the error bound for the Legendre interpolation