Chapter 8, Section 8.5, Question 028 Your answer is partially correct. Try again. Let f(x, y) = 6x2 + ky2 + 36xy. Determine the values of k (if any) for which the critical point at (0,0) is a saddle point, a local maximum or a local minimum. (a) The critical point is a saddle point when (enter NA if there is no condition on k that gives a saddle point). (b) The critical point is a local maximum when (enter NA if there is no condition on k that gives a local maximum). NA (c) The critical point is a local minimum when (enter NA if there is no condition on k that gives a local minimum).