1. (10 points) For the following function F(x, y, 2) = 2x' + 3y' + 423 + ay + 2yz + 3xz -5 use the implicit-function rule to find dy/Or and evaluate it at (x, y, z) = (1, -1, 2). (a) Give the analytical expression for dy/Or. (b) Give the numerical value for dy/Or evaluated at (c, y, 2) = (1, -1,2)