7>5x^2/b^2+y^2/a^2=1,焦点F在y轴上b^2=5,a^2=7c^2=7-5=2,c=√2F1(0,-√2),F2(0,√2)顶点A1(0,√7),A2(0,-√7)F1为顶点,a'=√2.a'^2=2顶点为焦点,c'=√7,c'^2=7b'^2=c'^2-a'^2=5双曲线方程:y^2/2-x^2/5=1...