近日听了一堂富阳市教研室举办的人教版普通高中课程标准实验教科书《数学》的研究课,课题是“正弦函数的图象”.执教教师是用教材介绍的正弦线方法来作正弦函数图象的,教师的讲解能从学生的知识经验出发,思路自然流畅,学生也基本掌握正弦函数的作图.但对教师(包括评课教师)的两点讲法笔者 Recently, I listened to a study class in the mathematics textbook for the senior high school curriculum of the People’s Education Publishing House held in Fuyang City. The topic was “sine-function image”. The coaches used the sine-line method introduced in the textbook to make a sine. The function image, the teacher’s explanation can start from the students’ knowledge and experience, the thoughts are natural and smooth, and the students also master the drawing of the sine function. But the two points of the teacher (including the evaluation teacher)