已知椭圆C:x^2/a^2+y^2/b^2=1(a>b>0)的离心率为√3/2,
问题描述:
已知椭圆C:x^2/a^2+y^2/b^2=1(a>b>0)的离心率为√3/2,
过右焦点F且斜率为k(k>0)的直线与C相交于A.B两点若AF=3FB,则k=?
答
e = √3/2 → c/a = √3/2 → b/a = 1/2 椭圆C:x^2/4b^2 + y^2/b^2 = 1 设直线 AB:my = x - c = x - √3b设A(x1,y1),B(x2,y2)AF/BF=3 → ly1/y2l = 3 直线AB代入椭圆 x^2+4y^2 = 4b^24b^2=(my+√3b)^2+4y^2=(m^2+4)...