18.02SC MattuckNotes: Second Derivative Test
ocw.mit.edu › courses › mathematicsThe second-derivative test for maxima, minima, and saddle points has two steps. f x (x, y) = 0, 1. Find the critical points by solving the simultaneous equations f y(x, y) = 0. Since a critical point (x0,y0) is a solution to both equations, both partial derivatives are zero there, so that the tangent plane to the graph of f(x, y) is horizontal. 2.