分类即分类讨论,是指当问题所给的对象不能进行统一研究时,就需要对研究对象按某个标准分类,然后对每一类分别求解得出每一类的结论,最后综合各类结果得到整个问题的解答即结论的整合.实质上,分类讨论是“化整为零,各个击破,再积零为整”的数学策略. Classification is classified discussion, refers to the problem given to the object can not be a unified study, you need to study the object according to a standard classification, and then each category were solved for each type of conclusion, the final combination of various types of results The answer to the whole question is the integration of the conclusion.In essence, the disagreement is the mathematical strategy of “tidy up to zero, break through each one, accumulate zero again ”.