二次方程

In order to avoid this type of attack, a new S-box design criterion is presented.

为了防止利用这些二次方程进行的代数攻击，本文提出一个新的S盒设计准则。

The new method gives out a set of equations based on the fundamental algebra rules that principal stress trace obeys and the essential attributes it possess, we then combine these equations with further information described in this paper leading to an exact description of the conic representing the principal stress traces.

该方法是根据主应力迹线满足过任意三条等倾线的主应力都可以用二次曲线来描述这一条件，再利用主应力迹线本身所具有的性质列出方程组解算出描述主应力迹线的一元二次方程，然后根据方程描绘出所求的主应力迹线。

Through teaching the Pythagoras theorem and the make-square method of quadric equation with one unknown, the teaching practice of using mathematics history during mathematics teaching of the secondary school is researched deeply, so the educational value of mathematics history is embodied well.

第四、通过勾股定理的教学和一元二次方程的配方法的教学，更深入地进行了中学数学教学中利用数学史的教学实践研究，更好地体现了数学史的教育价值。

Numerical calculation of the specific roots of the quadratic equation, this is more important for engineering calculations.

详细说明：数值计算中的二次方程求根具体程序，这对于工程计算比较重要。

This program calculates the root of the quadratic equation with very common and simple algorithms.

这个程序能用非常普通和简单的算法来计算一个二次方程的根。

But what is the point of teaching a chil d to solve a quadratic equation?

但是教会他去解二次方程的目的又何在呢？

Find the roots of a quadratic equation.

找出二次方程式的根。

This function solves a standard quadratic equation .

这个函数求解一个标准的二次方程。

A quadratic equation usually has two different solutions.

二次方程式通常都有两个不同的解。

B Using the result of, form a quadratic equation in x with roots and

a 求和。利用的结果，求两个根是和+并以 x 为变数的二次方程。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。