教材是高考命题的重要依据 ,教材中有一些典范性题目 ,它们或者是重要的结论 ,或者体现某种数学思想方法 ,或者是某个一般数学命题的具体形式 ,它的延伸、转化和拓广 ,呈现出丰富多彩的数学内容 ,这往往是编拟高考试题的源泉 .因此 ,我们必须充分重视对课本典型例、习题的探究 Textbooks are an important basis for college entrance examination propositions. There are some typical topics in the textbooks. They are either important conclusions or embody a certain mathematical thinking method or a specific form of a general mathematical proposition. Its extension, transformation, and extension , showing a variety of mathematics content, which is often the source of the preparation of high test questions. Therefore, we must pay full attention to the typical examples of textbooks, exercises