1) Whistler, very popular ski hill in BC, welcomes lots of skiers in the winter season. a) A skier's height 2: at (3:, y), measured from the ground, is modeled by z = f(a:,y) = 2 3:2 +3933; y3 + elmD2. If the skier starts at the point (1, 1), in which direction should the skier ski if he wants to move downhill the fastest? What is the rate of descent in this direction? b) When the skier moves downhill, his blood pressure is modeled by the function of three variables in = P(a:, y, 2) at every point (:13, y, z) on the hill. If his path is described by as : 2sin(t), y : 200s(t), z = 7r it. nd the rate of change of the skier's blood pressure at t = g using the data below: Px(2,0,1r/2) = 4, Px(0, 2,7r/2) = 1 Py(2,0,1T/2) = 2, Pym, 2,7r/2) = 1 Pz(2,0,7r/2) = 1, 132(0, 2,7r/2) = 2