文[1]例举了回避分类讨论的五种技巧,阅后获益匪浅.结合本人的教学实践,感到还有以下四种方法在处理此类问题时比较常用,作为前文的补充,特撰写此文,供同行参考.1　利用函数性质,回避讨论例1　证明不等式ｘ1-2ｘｘ2(ｘ≠0).分析　通常做法是按ｘ0和ｘ0两种情况进行分类讨论, The article [1] exemplifies five techniques that evade the discussion of classification. After reading it, they benefited a lot. In combination with my teaching practice, I feel that there are the following four methods that are commonly used when dealing with such issues. As a supplement to the foregoing, This article was written for reference by the peers. 1 Using the properties of the function, we evaded the discussion of Example 1 to prove the inequality x1-2xx2(x ≠ 0). The analysis is usually performed by classifying and discussing both x0 and x0 conditions.