Question

已知椭圆的两个焦点分别为F1(0,-2根2),F2(0,2根2)

Answer 1

e=2√2/3,c=2√2,e=c/a,a=c/e=3,b=1,

y^2/9+x^2=1,

y1^2/9+x1^2=1,(1)

y2^2/9+x2^2=1,(2),

k=(y1-y2)/(x1-x2),

k*y0/(-1/2)+9=0,

k=9/(2y0),0