分类讨论是数学解题中的一种重要思想方法,它一般是在原问题不能统一解决的情况下,将其分解成相互独立的若干子问题来处理,最后综合这些子问题的解答,得到对整个原问题的解答。 Classification discussion is an important way of thinking in mathematical problem solving. It is generally handled in the condition that the original problem can not be solved in a unified way and then decomposed into several sub-problems that are independent of each other. Finally, the solution to these sub-problems is obtained, The answer to the original question.