求作初等曲线的切线,方法较多,文章屡有发表。本文试图从导数的应用出发,另辟道路,作出新的尝试。可供中学教师作为辅导学生课外活动时参考。 函数y=f(x)在点x_0处的导数f′(x_0)的几何意义,就是曲线y=f(x)在点x_0处的切线的斜率。 For the tangent of the elementary curve, there are many methods. The article has been published repeatedly. This article attempts to start with the application of derivatives, open up new paths, and make new attempts. It can be used as a reference for secondary school teachers as counselling students for extracurricular activities. The geometric meaning of the derivative f′(x_0) of the function y=f(x) at the point x_0 is the slope of the tangent of the curve y=f(x) at the point x_0.