Suppose (0, 2) is a critical point of a function g with continuous second derivatives. In each case, what can you say about g?

(a) gxx(0, 2) = −1, gxy(0, 2) = 6, gyy(0, 2) = 1

(b) gxx(0, 2) = −1, gxy(0, 2) = 2, gyy(0, 2) = −8

(c) gxx(0, 2) = 4, gxy(0, 2) = 6, gyy(0, 2) = 9