solve all the questions

Work Problems: (60 points) You must provide clear and complete solutions for each of the following work problems. Question 1 [30 points] a) [12 points] Find all the critical points of the function f(x, y) = xy(2y + xy + >). b) [8 points] Classify all the critical points of f to determine its possible maximum, minimum and saddle points. Justify your answer. c) [10 points] Evaluate the following double integral by switching the order of integration Show your detail work. 8 + y dydx