Question

椭圆E:x^2/a^2+y^2/b^2=1(a>b>0)的右焦点F2与抛物线y^2=4x的焦点重合,过F2作与x轴垂直的

Answer 1

F2(1,0) a^2=1+b^2

将x=1代入y^2=4x |y1-y2|=CD=4

1/(1+b^2)+y^2/b^2=1 |y3-y4|=ST=2b^2/(1+b^2)^(1/2)

2根号2=2(1+b^2)^(1/2)/b^2

b=1

a^2=2

x^2/2+y^2=1

对不起字数限制,你继续追问