二次根式是初中数学中的一个难点.同学们在解题时常会出现计算出错、概念混淆或考虑不周等错误.对这些错误进行归纳和总结非常有必要.同学们只有从错误当中获得信息反馈,才能提高解题能力.一、概念不清二次根式的性质比较多,同学们理解这些性质时往往会忽略这些性质成立的条件,导致错用性质.而有时候即使错用某些性质,但是结果也能正确,所以这个问题往往得不到同学们的关注.下面我们就从这个例子来 Secondary root is a difficulty in junior high school mathematics students often have problems of calculation error, concept confusion or ill-considered, etc. It is necessary to summarize and summarize these mistakes.The students only get the information from the mistakes Feedback, in order to improve the ability to solve problems.First, the concept of unclear secondary root more nature, students understand these properties tend to ignore the conditions of these properties set up, leading to misuse of the nature and sometimes even misuse of certain properties, But the result can be correct, so this question often can not get the students’ attention. Here we will come from this example