实二次型正定性的一个判定定理的又一种证明

摘要

给出下列定理的又一种证明：一个实二次型是正定的当且仅当它的矩阵的一切顺序主子式全大于零。%In this paper,we give another proof of the following theorem： a real quadratic form is positive definite if and only if all leading principal minors of its matrx are greater than zero.