抛物线的一些性质

Some Propositions on Parabolas

近年,在研究射影几何在二次曲线上的运用中,发现有些平面几何问题用射影几何研究更自然、条理更清楚,而用平面几何方法处理则有难度.将二次曲线中的抛物线放在拓广平面上,借助射影几何中的Pascal定理、Steiner定理,给出了抛物线一些有趣的性质.

In recent years, the research in the use of the projective geometry on the conic, found some plane geometry problems in projective geometry research more natural, organized more clearly, and treated with plane geometry method is difficult. The quadratic curve on extension of the parabolic surface, with the help of Pascal theorem, Steiner in projective geometry theorem, parabolic some interesting properties are given.