文 [2 ]在文 [1 ]的基础上给出如下一个换算公式 .定理　ＡＢ是过圆锥曲线焦点Ｆ的弦 ,其长度为ｄ ,ＡＢ相对于焦点所在对称轴的倾角为θ(θ≠90°) ,ｔａｎθ=ｋ ,ｅ为离心率 ,ｐ为焦点到相应准线的距离 ,则有ｄ与ｋ的关系式 :ｄ=2ｅｐ(1 +ｋ2 )｜ 1 +ｋ2 -ｅ2 ｜ 或ｋ2 =ｅ2 The paper [2] gives the following conversion formula on the basis of [1]. Theorem AB is the chord of the focal point F of the hyperconic curve, its length is d, and the inclination of AB relative to the axis of symmetry of the focal point is θ (θ≠90). °), tan θ = k, e is the eccentricity, and p is the distance from the focal point to the corresponding guideline, then there is a relation between d and k: d=2ep(1 +k2 )| 1 +k2 -e2 | or k2 =e2