一元二次方程问题中,常常有一些容易被忽视的问题,使许多学生造成错解,为此撰写本文,供大家解题时参考.一、忽视一元二次方程的二次项系数不能为零例1关于x的一元二次方程(m2-4)x2+(2m-1)x+1=0(其中m为实数)的两个实数根的倒数之和为S,求S的范围.错解由判别式得Δ=(2m-1)2-4(m2 In the quadratic equation of one yuan, there are often problems that are easily overlooked, which cause many students to make mistakes. For this reason, this article is written for everyone to refer to. I. Ignoring quadratic equations of a quadratic equation cannot be zero Example 1 The sum of the reciprocals of the two real numbers roots of the unary quadratic equation (m2-4)x2+(2m-1)x+1=0 (where m is a real number) for x is S, find the range of S. From the discriminant, Δ=(2m-1)2-4(m2)