negative semi-definite quadratic form

例句：

1. 1. In linear algebra,a negative definite quadratic form isone that has no positive eigenvalues.
   在线性代数中，负定二次型是指没有正特征值的二次型。
2. 2. The negative definite quadraticform of the matrix A is used tofind the smallest eigenvalue.
   矩阵A的负定二次型用于找到最小的特征值。
3. 3. The negative definite quadraticform is important in solving systems of equationswith large numbers of variables.
   负定二次型在解决具有大量变量的方程系统中非常重要。