导数,作为解决与函数有关问题的强有力工具,越来越受到高考命题专家的重视。其中,利用导数解决函数恒成立问题或存在性问题中参数的取值范围,更是成为近年来高考的热点。解决这类问题的关键是运用等价转化的数学思想,下面笔者根据教学经验,通过自编的一个题目介绍一下此类问题的解法,期望 Derivatives, as a powerful tool for solving problems related to functions, are increasingly valued by experts in entrance exams. Among them, the use of derivatives to solve the problem of constant function or existence of parameters in the range of values, but also become a hot spot in recent years college entrance examination. The key to solve this kind of problem is to use the equivalent conversion mathematical thought, following the author based on teaching experience, through a self-made introduction to the problem of such a solution, expectations