双曲线x2/a2-y2/b2=1(a>0,b>0)的左右焦点分别为F1,F2,线段F1F2被点(B/2,0)分成3:2两

F1F2被点(B/2,0)分成3:2两段
b/2+c:c-b/2=3:2
c=5b/2
c^2=25b^2/4=25(c^2-a^2)/4
4=25(1-a^2/c^2)
4/25=1-1/e^2
e^2=25/21
e=5√21/21