《两角和与差的三角函数》一章教材的特点是公式多、系统性强、题目多、方法灵活。传统教法是按教材的先后顺序将所有公式一一传授,我们从实践中体会到这样教不利于突出公式之间的内在联系,在学生头脑中难以形成一个整体观念,也不利于能力的培养和提高。根据本章教材的特点以及学生的学习情况,我们认为《两角和与差的三角函数》采用“单元教学法”是有益的,也是可行的。我在本章实施的“单元教学法”概括起来是八个字:“整章齐下,纵横结合”。具体地说,是将教学的全过程分为两大步进行: 一“纵向教学”。在用坐标法证得cos(α+β)=cosαcosβ-sinαsinβ的基础上,让学生在教师指点下,推导出全部和、差、倍、半、和积互化公 The chapter “Chapter Two of Trigonometry and Difference Trigonometry” is characterized by many formulas, strong systematicness, many topics and flexible methods. According to the traditional teaching method, all the formulas are taught one by one according to the order of the textbooks. From experience, we realize that teaching this way is not conducive to highlighting the intrinsic relations among the formulas. It is difficult to form a holistic concept in the students' minds, nor conducive to the cultivation of abilities And raise. Based on the characteristics of the textbook and the students' learning situation, we think it is beneficial and feasible to adopt “unit teaching method” for the “two-angle and one-for-all trigonometric functions.” The “unit teaching method” that I carry out in this chapter can be summed up in eight characters: “The whole chapter, under the vertical and horizontal combination.” Specifically, the whole process of teaching is divided into two major steps: a “longitudinal teaching.” On the basis of using the coordinate method to prove that cos (α + β) = cosαcosβ-sinαsinβ, let the students deduce all the sum, difference,