The temperature at a point (x, y, z) is given by T(x, y, 2) = 400e-x2 - 5/2 - 922 where 7 is measured in C and x, y, z in meters. (a) Find the rate of change of temperature at the point P(4, -1, 4) in the direction towards the point (6, -4, 6). oc/m X (b) In which direction does the temperature increase fastest at P? (c) Find the maximum rate of increase at P