If you have a quadratic objective function, is this always convex (or concave)? It sounds logical as you think of the shape of a parabola. However, I read that the Hessian can be negative-definite and then the quadratic function is non-convex. Can someone clarify this and maybe give some examples?
2026-03-30 06:14:29.1774851269
Is a quadratic function always convex in a quadratic program (QP)?
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