1. The problem statement, all variables and given/known data Question 2 from http://math.berkeley.edu/~mcivor/math53su11/solutions/hw6solution.pdf here. I do not understand b) and e). How do I think of the slope with respect to y? 2. Relevant equations 3. The attempt at a solution I do know that the partial derivatives are the slopes of the tanget lines. I do know that fx < 0 as the slope is negative there (at point P), but I do not understand how the slop in terms of y looks.