Machine Learning, Gradient Descent, Hessian Matrix, Optimization, Artificial Intelligence.
(Saddle Point): Consider a mountain pass. At the pass itself, the curvature changes direction (from concave up on one side to concave down on the other). The Hessian will have eigenvalues of opposite signs. Example Equation: f(x, y) = x^2 - y^2 (saddle point at (0, 0)) The Hessian at (0, 0) is H(f)