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一元二次方程是初中代数的重要内容,然而很多同学由于受思维定势的影响,往往会忽视含有字母系数的一元二次方程中的隐含条件,致使解答陷入误区.具体表现主要有以下几方面:一、忽视二次项系数a≠0导致字母系数取值范围扩大例1已知关于x的一元二次方程(a2-1)x2+2(a+2)x+1=0有实根
The one-dimensional quadratic equation is an important content of junior high school algebra, but many students often ignore the implicit conditions in the one-member quadratic equation containing the letter coefficients because of the influence of the mindset, resulting in misunderstandings. The specific performance is mainly as follows: Aspects: I. Ignoring the coefficient a≠0 of the quadratic term leads to an increase in the range of the letter coefficient. Example 1 It is known that the quadratic equation (a2-1)x2+2(a+2)x+1=0 with respect to x is true. root