函数方程相关的函数问题,一直是函数知识中较难的学习内容,尤其更以函数方程确定的抽象函数为甚.定义:含有未知函数的等式称为函数方程.解函数方程的问题,就是求能使函数方程成立的一个函数或一类函数的集合. Function problems related to the function equation have always been difficult to learn in functional knowledge, especially the abstract functions defined by the function equations. Definition: Equations with unknown functions are called functional equations. The problem with solving functional equations is that Find a function or set of functions that will hold the function equation.