definition for saddle point?

Answer 1

Point in a two-dimensional spline where the spline is horizontal but not at a minimum or maximum.

Assuming you have a bivariate twice differentiable function, z = f(x,y), a saddle point is a point (x,y) such that the derivatives df / dx = 0; df / dy = 0;

moreover, d^2f / dx^2 and d^2f / dy^2 have opposite sign.

Answer 2

A saddle point is where the derivatives of a 3D graph are concave up in one coordinate plane and concave down in another coordinate plane. They don't match, so you don't have a clear minimum or maximum. If you draw them out, they kind of look like a saddle.

Answer 3

A point where all the first partial derivatives of a function vanish but which is not a local maximum or minimum. For a matrix of real numbers, an element that is both the smallest element of its row and the largest element of its column, or vice versa. For a two-person, zero-sum game, an element of the payoff matrix that is the smallest element of its row and the largest element of its column, so that the corresponding strategies are optimal for each player, given the strategy chosen by the other player