Question 2. Suppose f is a function such that D (1,2,2) f (x, y, z) = 3x + 2y arctan(z) + z and Do, 1,1) f (x, y, z) = x + y arctan(z). 2.1. Find D(1,3,3) f(x, y, z) (as a function of (x, y, z)). 3 points 2.2. Let g(s, t) = f(1 + s, 1 + 2s + t, 7/4 + 2s + t). Find Vg(0, 0). 4 points