Part a. Let If VF(2, 1, 3) = (a, b, c) then a = b == c = Part b. Let x + By + Cz = D, be the tangent plane to the surface at the point (2,1,3). Then B = C = D = F(x, y, z) = 9z 1+xy4* Z 1 + xy 33 Answer entry help: 1. No blank spaces are allowed in the answer fields 2. If your answer a = Z please write only Z in the answer box. Note that a = is already written. Thus, if you put a = Z in the answer box, the system will read this as a = a = Z and will treat as a wrong answer. 3. Write v^z Write v*z Write In(z) for (multiplication of by z) for Inz (parenthesis are required) Write sqrt(z) for 2 (parenthesis are required) Write sin(z) for sin z (parenthesis are required) Write pi for