一个焦点F1(0,-2倍根号2),对应的准线为Y=-4分之9倍根号2,
对应的准线为Y=-a^2/c=-9√2/4
焦点F1(0,-2倍根号2),c=-2√2
a^2=9
c^2=(2√2)^2=8
b^2=a^2-c^2=9-8=1
椭圆标准方程x^2/9+y^2=1