Machine Learning, Gradient Descent, Hessian Matrix, Optimization, Artificial Intelligence.
signifies an upward curvature in the x-direction. The other positive eigenvalue 4 indicates a stronger upward curvature in the y-direction, making the overall function concave up. Negative Definite Hessian (Concave Down): You can just reverse the logic of the previous paragraph. Indefinite Hessian