封闭型函数曲线问题既具有一定的抽象性,对函数作图能力的要求也较高,是历年竞赛考查的重要内容.下面介绍其解法,供同学们参考. The closed function curve problem has not only a certain degree of abstraction, but also a high requirement for the function mapping ability. It is an important content of the contest examination in previous years. The following describes the solution method for the students to refer to.