Question 4. Given the function f(5) = 111(2 cos(2s)) and the mesh 5i = s+ik, where so: ,9 determine the backward finite difference for the first derivative of f with step size k: % at mesh point 2': 3. At the same point, also calculate the exact first derivative f'(si). Calculate the absolute value of the error of the finite difference approximation at the point Si. Work to at least 6 decimal places throughout and enter your answers to 2 decimal places. (a) Enter the finite difference approximation [:1 (b) Enter the exact derivative l:] (c) Enter the absolute error [:] (d) If we were to divide the step size by 10, the error will be approximately multiplied by a factor of \\/ Select ' 'IO