抽象函数是一种重要的函数模型,问题表现为某函数满足若干性质表达式,在此基础之上探讨与此函数相关的问题.这类问题没有具体的解析式可用,解决起来思维跨度大,对抽象思维能力要求很高.“赋值法”是解决抽象函数问题的重要途径.它可以是给变量赋以符合已知条件的一个或几个值, Abstract function is an important function model, the problem is expressed as a function to meet a number of properties of expression, on this basis to explore the problems associated with this function.This type of problem is not a specific analytical available, to solve a large span of thinking, The abstract thinking ability is very high.Association method is an important way to solve the problem of abstract function.It can be assigned to the variable to meet the known conditions of one or several values,