一、有关分类的一些常识 在中学数学教学里,无论是讲述概念、推导公式、证明定理或解答习题,经常要用到分类这一逻辑方法。 有些问题,如果在给定条件下有多个情况,需要运用分类方法把可能存在的一切情况都列举出来,一一加以研究,然后加以总括作出结论。 First, some common sense about classification In the middle school mathematics teaching, whether it is about the concept, deduction formula, proof theorem or answer exercise, often use the classification of this logical method. Some problems, if there are multiple situations under given conditions, need to use classification methods to list all possible situations, study them one by one, and then make conclusions in an aggregate way.