quadratic formula

The inertia theorem of the quadratic form was conventionally proved by applying the theory of a set of linear equations ( see ( 1) p.214), or by using the dimensional formula of subspace ( see ( 2) p.335).

二次型的惯性定理通常用线性方程组理论（参见（1）P.214）或用子空间维数公式（参见（2）P.335）加以证明。

This paper gives the second order ample condition of Lagrange multiplier rule of constrained extreme value with the quadratic form, and proves it by use of counterevidence with the help of Lagrange theorem of mean value and Taylor formula;

以二次型形式给出约束极值拉格朗日乘数法的一个二阶充分条件，并用反证法由拉格朗日中值定理及泰勒公式予以证明；

Real Coefficient Quadratic Equations Formula of Root on Real Commutative Algebra

交换代数中二次方程的求根公式

After deriving Swt from the model, we find out that the water saturation equation is a quadratic equation about Swt, so its solution is very simple and obtained by using the standard quadratic-root formula.

通过研究混合泥质砂岩有效介质通用HB电阻率模型的求解方法，表明模型导出的关于S（wt）的方程是一个一元二次方程，可用求根公式求解，解法非常简单。