笔者近日在对圆锥曲线内点性质研究时 ,发现了圆锥曲线内点的一个新颖有趣的性质 .图 1性质 1　设Ｐ(ｘ0 ,ｙ0 )是椭圆Ｅ内部一定点 (异于Ｅ的中心Ｏ) ,过点Ｐ引直线ｌ交椭圆Ｅ于Ａ、Ｂ两点 ,以ＯＡ、ＯＢ为邻边作平行四边形 (当Ａ、Ｏ、Ｂ三点共线时 ,可视为退化情形 ,下同)Ｏ The author recently discovered a novel and interesting property of the point within the conic section when studying the properties of the conic section. Figure 1 Properties 1 Let P(x0, y0) be a certain point inside the ellipse E (different from the center O of the E). , P point over the straight line l cross ellipse E in A, B two points, with OA, OB as the adjacent side for the parallelogram (When A, O, B three points collinear, can be considered as a degenerate situation, the same below)