一元二次方程在初中数学中占有重要的位置,也是初中数学教学的一大难点。学生在解答一元二次方程有关的问题时,往往考虑不周,顾此失彼,而导致结论不完整,甚至结论错误。在此,笔者就解一元二次方程容易出现的错误作几点警示。警示一:注意二次项系数不为零的隐含条件例1.已知关于x的方程(m-2)x2+(2m+1)x+m-2=0有两个不相等的实数根,求实数m的取值范围。错解:∵该方程有两个不相等的实数根 The quadratic equation plays an important role in junior high school mathematics and is also a major difficulty in junior high school mathematics teaching. When students are answering questions related to the quadratic equation, students often think ill-considered and lose the other, leading to incomplete conclusions and even wrong conclusions. At this point, the author on the solution of a quadratic equation easy to make mistakes for a few warnings. Caution 1: Notice the implicit condition that the quadratic coefficient is not zero Example 1. Known equation for x (m-2) x2 + (2m + 1) x + m-2 = 0 There are two real numbers that are not equal , Realistic m number of values. Wrong Solution: ∵ There are two unequal real roots in the equation