Question 13, 14.5.27 HW Score: 89.22%, 15.17 of 17 points ((33 ' > Homework Se... Part 2 0f2 @ Points: 0.5 of 1 Sketch the curve f(x,y) = c together with Vf and the tangent line at the given point. Then write an equation for the tangent line. xy=-16, (4,4) Choose the correct graph below. The equation for the tangent line is El. (Type an equation using x and y as the variables.) Homework: Se... Question 14, 14.5.29 HW Score: 8 Part 5 of 7 > Points: 0. Let f(x,y) = x" - xy + y - y. Find the directions u and the values of D,,f(1, - 1) for which the following is true. a. Duf(1, - 1) is largest b. Duf(1, - 1) is smallest C. D, f(1, - 1) = 0 d. D, f(1, - 1) = 4 e. Duf(1, - 1) = - 3HW Score: 89.22%, 15.1 0 Points: 0 of 1 Homework: Se... Question 15, 14.5.31 In what directions is the derivative of f(x,y) = xy + y2 at P(6,5) equal to zero? Select the correct choice below and, if necessary, ll in the answer box to complete your choice. A- u=|:| (Simplify your answer. Use a comma to separate answers as needed. Type your answer in terms of i and j.) C) B. There is no solution