初二学生在学习“二次根式”时常常出现这样那样的解题错误 ,为了使学生在解二次根式习题时做到会而对 ,现列举一些最常见的错解 ,并对错误的原因作简要的分析 ,从此吸取教训。一、考虑问题不周密例 1　ｘ为何值时 ,式子 13ｘ - 2 在实数范围内有意义 ?错解 :由 13ｘ - 2 ≥ 0 Students of grade two often have such problem solving errors when they are studying the “secondary root pattern”. In order to make students solve problems when they are solving secondary root exercises, we now list some of the most common misconceptions and the reasons for the errors. Make a brief analysis and learn from it. First, consider the problem is not accurate 1 x why when the value, the formula 13x - 2 meaningful in the real range ? wrong solution : from 13x - 2 ≥ 0