Question

a point (a,b) is said to be saddle point if at (a,b)

Answer 1

Answer:

If D < 0, f is said to have a saddle point at (a, b). ... If (a, b) is a saddle point of f then F(x, y) is indefinite, this will be positive at some points and negative at others. Theorem. Let f be a function with continuous second partial derivatives in an open set U in the plane and let (a, b) be a saddle point in U.