坐标平移对 双曲线形状无影响
所以
k1 = b1/a1
k2 = b2/a2
e1/e2 = (c1/a1)/(c2/a2) = √ [ (a1^2 +b1^2)/a1^2 / (a2^2 + b2^2)/a2^2 ]
= √ [ (1+k1^2)/(1+k2^2) ]
把分子的1变成 (k1k2)^2
= √ [ k1^2 (k2^2+1)/(1+k2^2) ]
= √ k1^2
= k1
坐标平移对 双曲线形状无影响
所以
k1 = b1/a1
k2 = b2/a2
e1/e2 = (c1/a1)/(c2/a2) = √ [ (a1^2 +b1^2)/a1^2 / (a2^2 + b2^2)/a2^2 ]
= √ [ (1+k1^2)/(1+k2^2) ]
把分子的1变成 (k1k2)^2
= √ [ k1^2 (k2^2+1)/(1+k2^2) ]
= √ k1^2
= k1