III. If f(x, y) = x cosy - y'sinx + xy, then find all the second order partial derivatives. IV. Suppose that a cylinder is designed to have a radius of 4 inch and a height of 6 inch, but that the radius and height are off by the amounts dr = 0.02 and dh = - 0.3 . Estimate the resulting percentage error in the volume of the cone. 2 V. Given the series 1 X 4 4 4 3 If you differentiate the series term-by-term, what new series do you get