Question

椭圆y^2/a^2+x^2/b^2=1(a>b>0)的两个焦点为F1(0,-C)),F2(0,c)(C>0),离心率e=

Answer 1

把x=y-1代入椭圆得：y²/4+(y-1)²=1

5y²-8y=0

y1=0,y2=8/5

则：x1=-1,x2=3/5

所以,P(-1,0),Q(3/5,8/5)

画图知：tan∠poQ=-tan∠QOX=-K(OQ)=-8/3