论文部分内容阅读
一、基础知识“若实数x1、x2是方程ax2+bx+c=0(a≠0)的两个根,则x1+x2=-b/a,x1x2=c/a”,这一关系称之为韦达定理;其逆定理是:“若实数x1,x2满足x1+x2=-b/a,x1x2=c/a,则x1,x2是方程ax2+bx+c=a(a≠0)的两个根”,韦达定理及其逆定理在各类数学竞赛中具有广泛的应用,下面举例加以说明:二、应用举例1.用于求方程中参系数的值例1 设m是不小于-1的实数,使得关于x的方程x2+2(m-2)x+m2-3m+3=0有两个不相等
First, the basic knowledge “If the real number x1, x2 is the two roots of the equation ax2 + bx + c = 0 (a ≠ 0), then x1 + x2 = -b / a, x1x2 = c / a”, this relationship is called This is the Vedic theorem; its inverse is: “If the real number x1,x2 satisfies x1+x2=-b/a,x1x2=c/a, then x1,x2 is the equation ax2+bx+c=a(a≠0 ”The two roots of", Vedic theorem and its inverse theorem have a wide range of applications in various types of mathematical competition, the following examples illustrate: Second, the application of examples 1. Used to find the value of the parameters in the equation Example 1 Let m be A real number not less than -1 such that there are two inequalities in the equation x2+2(m-2)x+m2-3m+3=0 for x