曲线x^2/16+y^2/9=1与曲线x2^/9-m+y^2/16-m=1(0

题目

曲线x^2/16+y^2/9=1与曲线x2^/9-m+y^2/16-m=1(0

答案

x^2/16+y^2/9=1
焦点在x轴的椭圆
c^2=16-9=7
x2^/(9-m)+y^2/(16-m)=1(00
∴也是椭圆
∵16-m>9-m
∴焦点在y轴
c^2=(16-m-9+m)=7
∴焦距相等
选A