课本的许多习题都具有代表性、典型性和可塑性,研究这些习题,可以充分发挥课本的潜在功能,沟通知识间的联系,同时对促进学生钻研课本,提高解题能力及复习效益都有一定的积极作用.例如现行高中课本《平面解析几何》(必修)P110页第12题:如图1,从椭圆上一点 P 向 x 轴作垂线,恰 Many of the exercises in the textbook are representative, typical and malleable. To study these exercises can give full play to the potential functions of the textbooks and communicate the links between the knowledge. At the same time, they have a certain degree of importance in promoting students to study textbooks, improve problem-solving abilities and review the benefits. Active role. For example, the current high school textbook “Plane Analytic Geometry” (required) P110 page 12: In Figure 1, from the ellipse point P to the x axis as a vertical line, exactly