在函数单调性的教学中,教师通过创设情境——展示气温图象,一次函数、二次函数、反比例函数的图象.使学生很容易从图形直观上升到自然语言叙述——x增大(减小),y增大(减小).困难就在于如何由自然语言抽象到符号语言,这是本节的教学难点.最近笔者听了这节课,课后又认真翻阅了相关杂志,在笔者比较的几个教学设计中,教师都提出了以下的 In the monotonic teaching of function, the teacher creates images to show the images of temperature, first-order functions, second-order functions, and inverse proportion functions, making it easy for students to intuitively ascend from the graphic to the natural language narrative - Reduce), y increase (decrease). The difficulty lies in how to abstract from the natural language to the symbolic language, this is the teaching of difficult points.Recently I listened to this class, after class and carefully read the relevant magazines, in I compare several teaching design, the teachers have made the following