中学数学中介绍了一些求函数的极值或最值的初等方法。在运用这些方法解某些问题时,有些同学只是机械地套用,不注意对具体条件的分析,因而得出片面的甚至是错误的结论。教师应加以引导。举例如下。第一、忽略了变量的取值范围。 High school mathematics introduces some elementary methods for finding the extreme or maximum values ​​of a function. In using these methods to solve certain problems, some students just apply them mechanically, and do not pay attention to the analysis of specific conditions, and thus come to one-sided or even wrong conclusions. Teachers should be guided. Examples are as follows. First, the value range of the variable is ignored.