1. Find the maximum rate of change of f(x, y) = sin(xy) at the point (0, 1) and the direction in which it occurs. 2. Find the absolute minimum and the absolute maximum values of f on the set D. Note that the set D is a square, and, beyond the overall critical points of f (x, y), you will need to find critical and enpoints for all four edges of the square. (See the problem with the triangle that we worked out in class on 10-5.) f ( x, y ) = 4x + 6y - x2 - y D = { ( x, y) : 0