我们把没有给出具体解析式的函数称为抽象函数.抽象函数问题往往只给出了一些体现函数特征的式子,由于表现形式的抽象性,显得很神秘,使得这类问题成为函数内容的难点之一.另一方面,由于抽象函数问题可以全面考查学生对函数概念和性质的理解,同时又将函数的定义域、值域、单调性、奇偶性、周期性和图象集于一身,所以在高考和竞赛中不断出现这类问题.由于解析式的不确定,抽象函数问题解决起来更困难一些,一般用赋值法来寻求函数的特殊 We call functions that do not give a specific analytic function an abstract function, which often gives only some expressions that reflect the characteristics of the function, which are mysterious due to the abstraction of the representation, making such problems functionally On the other hand, due to the abstract function problem, students can comprehensively examine the students’ understanding of the concept and nature of the function, at the same time, combine the domain of function, range, monotonicity, parity, periodicity and image together, So in college entrance examination and competition continue to appear such problems due to analytical uncertainty, the abstract function to solve some of the more difficult problems, the general assignment method to find the special function