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Which of the following most correctly de- 1. saddle (3, -3), local max (-3, 3) scribes the behaviour of the graph of the func- tion O 2. local max at (3, -3), (-3, 3) f(x, y) = 2(x +y)(xy + 9) + 4. 3. local max at (3, 3), (-3, -3) 4. saddle-points at (3, 3), (-3, -3) 5. saddle-points at (3, -3), (-3, 3)Locate and classify the critical point of 1. local minimum at (2, - f(x, y) = In(xy) + 2y- -y - 2xy + 3, 2. saddle-point at (2, !) for x, y > 0. 3. local minimum at , 2) 4. local maximum at (2, -) 5. local maximum at , 2 6. saddle-point at ( -, 2)Determine the absolute maximum of 1. absolute max = 2+ v2 f(x, y) = alty2-x-y+1 O 2. absolute max = 2 on the unit disk 3. absolute max = 3 D = {(x, y) : a2 +y?