Suppose that the temperature at a point (as, y, z) is given by T($, y, z) = 80 + cos(7r:r) 312 Z2. (a). Find the rate of change of the temperature at the point (1, 2, 1) in the direc tion of the vector . (b). At the point (1, 2, 1), in which direction does the temperature increase most quickly? What is that maximum rate of change of temperature