所谓抽象函数就是未给出具体解析式的函数,由于其表达形式的抽象和性质的隐含不露,使得直接求解的思路常难以寻求,再加上还要用到赋值法和配凑技巧,使同学们对抽象函数问题比较害怕.其实,大量的抽象函数都是以中学阶段所学的基本函数为背景抽象而成的,我们称这类基本函数为背景 The so-called abstract function is a function that does not give a specific analytical expression. Because of the implicit nature of the abstraction and nature of its expression form, the direct solution is often difficult to find, plus the use of assignment methods and matching techniques. Students are more afraid of abstract function problems. In fact, a large number of abstract functions are abstracted from the basic functions learned in the middle school stage. We call this type of basic function as the background.