Machine Learning, Gradient Descent, Hessian Matrix, Optimization, Artificial Intelligence.
of the determinant of the Hessian, det(H(f)), tells us about the function's concavity at that point. Positive definite Hessian (all eigenvalues positive): det(H(f)) > 0 indicates the function is concave up (like a smiley face). Negative definite Hessian (all eigenvalues negative): det(H(f)) < 0