Definition:Positive Definite


 * Abstract Algebra:
 * Positive Definite Function on Ring: $\forall x \in R: \begin {cases} \map f x = 0 & : x = 0_R \\ \map f x > 0 & : x \ne 0_R \end {cases}$


 * Matrix Theory:
 * Positive Definite Matrix: a symmetric matrix whose eigenvalues are all strictly positive.

Also see

 * Definition:Positive