4. (4 points) Let \"9379) = 6002444272; (a) Calculate the gradient V f and the Hessian H. (1)) Use a tangent plane approximation to estimate f(3.02. 3.99). (c) Use a quadratic approximation to estimate f (3.02, 3.99). ) (d Use a calculator to compute the exact value of f (3.027 3.99). How accurate is your tangent plane approximation? How accurate is your quadratic approximation