他的主要著作是关于圆锥线的，但也写过其他方面的著作。
His chief work was on the conic sections but he also wrote on other subjects.
在特定条件下，椭圆锥与平面的截交线为圆。
Under definite conditions, the intersection of an elliptic cone with a plane is a circle.
解析几何中圆锥截线的一条封闭曲线，包含了与两个定点(焦点)之距离呈等值增加的所有点。
Closed curve, one of the conic sections of analytic geometry, consisting of all points whose distances from each of two fixed points (foci) add up to the same value.
应用推荐