1.本单元知识网络本单元是三角函数的起始内容,也是学习后继内容的根基.教材首先将角的概念推广到任意角,并引入弧度制的表示方法;在此基础上,定义了任意角的六种三角函数;然后介绍同角三角函数的基本关系式以及三角函数的诱导公式,它们是进行三角恒等变换的必备基础.本单元的 1. The unit of knowledge network This unit is the starting content of the trigonometric function, but also the basis for learning the successor content.Text first to generalize the concept of angle to any angle, and the introduction of radians system of representation; on this basis, the definition of any Then introduce the basic relations of the same-angle trigonometric functions and the induction formulas of the trigonometric functions, which are the necessary foundation for the triangular equivalent transformation.