Question 2 (i 2 marks) a. Let f(x,y) = si(x 122). i. Find f1 and j}. (2 marks) ii. Find fa, f , f\" and f\". Verify that fly 2 f\". Tip: Maple can be used to check partial derivatives. (4 marks) Let f(x,y)=x2 2.xy+y3 y. i. Find all stationary points of f (x y) and evaluate the function at each of them Tip: Sketch the curve(5) Twhere j; = 0 in one colour, and the curve(s) where fy = 0 in a different colour. Stationary points occur wherever two different colours intersect or overlap. (2 marks) ii. Use the second-derivative test to determine the nature of each stationary point. (2 marks) iii. Find the equation of the tangent plane to f (x, y) at the point (2, l)