中文翻译：The major axis of the ellipse is a and the minor axis is b The vertex radius of the ellipse is R = b2a The eccentricity of the ellipse is  = a2  b212a and the conic constant is k = 2 = b2  a

椭圆的长轴为a，短轴为b。椭圆的顶点半径为R = b2/a。椭圆的离心率为ε = (a2-b2)1/2/a，圆锥常数为k = -ε2 = (b2-a2)/a2。焦点之间的距离为2F，其中F2 = a2-b2。从表面顶点到焦点的距离为a±F。当k<-1时，表面是旋转双曲面。以下图示展示了双曲线的几何形状。LightTools只插入双曲线的一个分支。