Question 4 [19 marks] Given the function f(x,y) = (x2 y)2 +x3 3x2, (a) Compute the first-order partial derivatives and all the second-order partial derivatives of the function. (6 marks) (b) Find the stationary points and classify them using the second derivative test. (9 marks) (c) Determine whether f(x, y) has any global extreme points. (4 marks)