一元二次方程根与系数的关系是初中代数内容中的一个重点、难点,也是考试命题的热点.但是,同学们做此类题时常出错误,下面举例说明. The relationship between the root and the coefficient of the quadratic equation is not only a key point and difficulty in the content of junior high school algebra, but also a hot topic of the examination proposition. However, students often make mistakes when doing such a problem. The following examples illustrate.