Question 19 Let f(x, y) = 3x2y + y3 - 3x2 - 342 + 2. 1. How many critical points does f have? [ Select ] [ Select 2. P (-1, 1) and Q (0, 0) are two of the critical points of f. Classify the critical points P and Q using the second derivative test. . f has a [ Select ] at P. [ Select ] local max local min saddle point . f has a [ Select ] at Q. [ Select ] saddle point local min local max