论文部分内容阅读
若 x_1、x_2是一元二次方程 ax~2+bx+c=0的两个根,则对任意实数x,有 ax~2+bx+c=a(x-x_1)(x-x_2).本文将从恒等式角度探讨该结构的应用,你将看到,其应用广泛、独特,别具一格.一、用于求方程中待定的常数的值例1 若方程(x-a)(x-8)-1=0有两个整数根,求 a 的值.(90年全国初中联赛试题)解:设方程的两个整数根为 x_1、x_2,则(x-a)(x-8)-1=(x-x_1)(x-x_2),
If x_1 and x_2 are two roots of a quadratic equation ax~2+bx+c=0, then for any real number x, there is ax~2+bx+c=a(x-x_1)(x-x_2). This article will discuss the application of this structure from the perspective of identity, and you will see that its application is extensive, unique and unique. First, for the value of the constant to be determined in the equation Example 1 If equation (xa) (x-8) -1 =0 There are two integer roots, find the value of a. (90 national junior high school league questions) Solution: Let the two integer roots of the equation be x_1, x_2, then (xa)(x-8)-1=(x- X_1)(x-x_2),