negative definite

Let $A$ be an $n\times n$ symmetric real square matrix. If for any non-zero vector $x$ we have

 $x^{t}Ax<0,$

we call $A$ a negative definite matrix.

Title negative definite NegativeDefinite 2013-03-22 12:20:06 2013-03-22 12:20:06 drini (3) drini (3) 4 drini (3) Definition msc 15A48 PositiveDefinite PositiveSemidefinite QuadraticForm