如题~
要过程~~
谢谢
M(-a²/c,(ab)/c),向量F1M=(-a²/c+c,(ab)/c),向量F2M=(-a²/c-c,(ab)/c),
又向量F1M*向量F2M=-1/4,a^4/c^2-c^2+a^2*b^2/c^2=-1/4,化简得:b^2=1/4,b=1/2;
离心率为根号5/2,c^2/a^2=5/4,∴a^2+1/4/a^2=5/4,∴a^2=1
双曲线的方程x^2-4y^2=1