Question

设双曲线-=1的两焦点为F₁、F₂,A为双曲线上一点,且|AF₁|=8.5,则|AF₂|的值为(    )

A.40.5             B.0.5           C.16.5        D.16.5或0.5

Answer 1

解析:由双曲线定义||AF₁|-|AF₂||=2a,

即8.5-|AF₂|=±8.

∴AF₂=0.5或16.5.

答案:D