Hessian Determinant

The Determinant

$$Hf(x,y)\equiv\left\vert\matrix{ {\partial^2f\over \partial ... ...\over\partial y^2}\cr}\right\vert\hrule width 0pt height 4.8pt$$

appearing in the Second Derivative Test as $D\equiv Hf(x,y)$.

See also Second Derivative Test

References

Gradshteyn, I. S. and Ryzhik, I. M. Tables of Integrals, Series, and Products, 5th ed. San Diego, CA: Academic Press, pp. 1112-1113, 1979.