在实际问题中,题目中常出现如“时间最短、利润最大、费用最省、角度最恰当”等问题,求此类问题,可以从给定的数量关系中选取一个适当的变量,建立函数模型,根据目标函数的结构特征,动用导数最值理论或不等式性质去解决,简洁有效.本文拟通过例举说明导数在解实际问题中的应用.【 In practical problems, problems such as “the shortest time, the largest profits, the lowest cost, and the most appropriate angle” often appear in the questions. To find such questions, an appropriate variable can be selected from the given quantitative relationship and a function model can be established. According to the structural features of the objective function, the derivative theory or inequality property is used to solve the problem, which is concise and effective. This paper intends to illustrate the application of derivative in solving practical problems.