有一类抽象函数问题 ,常把与抽象函数有关的等式作为条件 ,在高考试题中频繁出现 ,怎样利用好这些等式是解决此类问题的关键 .本文介绍处理这类问题的几种解题策略 .一、利用递推关系与抽象函数有关的等式看作递推式 ,利用其递推关系寻找新的等式 .例 1　已知 f ( x)是定义在正 There is a class of abstract function problems. The equations related to abstract functions are often used as conditions and frequently appear in high test questions. How to make good use of these equations is the key to solving such problems. This article describes several problems in handling such problems. Strategy. 1. Using recurrence relations Equations related to abstract functions are treated as recursive, using their recurrence relations to find new equations. Example 1 Known that f (x) is defined in positive