笔者在教学中发现:椭圆和双曲线在顶点处的直角有一些类似的性质,这些性质对设计中学数学解析几何试题提供了很好的背景.这些性质本身又是中学解析几何能力训练的好题型.现叙述如下.图1定理1图定理1(如图1)设椭圆x2a2+2yb2=1(ab0)的上、下顶点分别为B1,B2.M,N是椭圆上的两动 The author found in the teaching that the right angles of the ellipse and the hyperbola at the vertices have some similar properties. These properties provide a good background for the design of middle school mathematics analytic geometry test questions. These properties are in themselves good topics for secondary school analytical ability training. Type. Now described as follows. Figure 1 Theorem 1 Figure Theorem 1 (Figure 1) Assume that the upper and lower vertices of the ellipse x2a2+2yb2=1(ab0) are B1, B2.M, respectively, and N is the two actions on the ellipse.