Consider the function f (x comma y comma z )equals4 x squared plus 3 y squared plus 3 z squared plus 3, the point p(1 comma 0 comma 3 ), and the unit vector bold uequalsleft angle negative startfraction 1 over startroot 2 endroot endfraction comma 0 comma negative startfraction 1 over startroot 2 endroot endfraction right angle . a. compute the gradient of f and evaluate it at p. b. find the unit vector in the direction of maximum increase of f at p. c. find the rate of change of the function in the direction of maximum increase at p. d. find the directional derivative at p in the direction of the given vector.