Suppose z = x sin y, x = 3s + 3t2, y = -10st. A. Use the chain rule to find and =2x sin y 6s+x cosy. cos y -10t =2x sin y-6t+x cosy. -10s as functions of x, y, s and t. B. Find the numerical values of and when (s, t) = (-3, 1). (-3, 1) = (-3, 1) = 12x sin y + 30x2 cos y