韦达定理在中学数学中占有重要地位,也是“中考”的热点。本文以近一、二年来中考题为例,介绍韦达定理的几个应用。1 求根的对称式的值或取值范围 例1.设x_1,x_2是方程2x~2-6x+3=0的两个根,则代数式x_2/x_1~2+x_1/x_2~2的值等于( )。 Weida’s theorem plays an important role in middle school mathematics and is also a hot spot in the “intermediate examination”. This article takes the exams in recent years or two as an example to introduce several applications of Vedic theorem. 1 Find the Symmetrical Value or Range of the Root Example 1. Let x_1,x_2 be the two roots of the equation 2x~2-6x+3=0, then the algebraic expression x_2/x_1~2+x_1/x_2~2 Equal to ().