QUESTION 6 Let f(I, y) - 2y - 2xy + 1' + 1 Find the local minimum points, local maximum points, and saddle points of f. 2 CALCULUS III: HIW 10 QUESTION 7 Find three positive numbers whose sum is 9 and whose product is as large as possible. QUESTION & Find the points on the surface = = ry + 5 which are closest to the origin. (Hint: express z' in terms of r and y, and use this to express the distance formula as a function of s and y. Then minimize this distance function, or its square.) QUESTION 9 Let f(x, y) = 1+ 2ry + = + 25 Find the local minimum points, local maximum points, and saddle points of f