分类讨论是一种逻辑方法,也是一种重要的数学思想、解题策略,它体现了化整为零、积零为整的思想与归类整理的方法.在高考中,用“分类讨论思想”来解决的问题频频显现.但对于不少代数题,由于变量复杂,代数式的结构、大小变化多样,如何确定分类对象、分类标准,从而合理分类,并非易事.事实上,代数题离不开代数式,其分类应依据有关代数式的特征,有条有理地进行.下面举例说明. Category discussion is a logical method, but also an important mathematical thinking, problem-solving strategy, which reflects the whole system is zero, the idea of ​​zero for the whole and sorting methods. Thinking "to solve the problem frequently.However, for many algebra problems, because of the complexity of variables, the structure of algebra, the size of the diversity, how to determine the classification of objects, classification criteria, so that reasonable classification is not easy.In fact, algebra problems Can not do without algebra, its classification should be based on the characteristics of algebraic style, in an orderly manner.