若双曲线的渐近线方程为3x±4y=0,则a/b=4/3,即b=(3/4)aa^2=(9/16)a^2+c^2 (7/16)a^2=c^2 e^2=c^2/a^2=7/16 e=√7/4
若焦点在x轴,则a=4;b=3 => c=√(a²+b²)=5 e=c/a=5/4若焦点在y轴,则a=3;b=4 =>c=5 e=c/a=5/3