二次曲线的主轴、焦点和准线研讨

Discussion on Spindle,Focus and Directrix of a Quadratic Curve

在探讨射影几何中定义的二次曲线的主轴、焦点和准线时,用射影几何的概念法可以分别得到抛物线、椭圆与双曲线的主轴、焦点和准线.由研讨得知在射影几何中定义的二次曲线的主轴、焦点和准线与解析几何中定义的二次曲线的主轴、焦点和准线是一致的.

This paper discusses the definition of second curves in the projective geometry of the spindle,the focus and directrix with the concept of projective geometry method.It is found that parabolic,spindle,focus and directrix of ellipse and Hyperbola can be obtained respectively.By the seminar was informed that define a conic in projective geometry analytic geometry and spindle,focus and directrix of second curves that are defined in the spindle,focus and the directrix is consistent.