Question

方程x²/(2-m)+y²/(m+1)=1表示焦点在y轴的双曲线时,求m的范围和焦点坐标

Answer 1

焦点在Y轴

m+1>0 and 2-m-1 and m>2

所以,m的范围是 m>2

c^2=(m+1)^2+(2-m)^2=2m^2-2m+5

焦点坐标（0,根号（2m^2-2m+5)),(0,-根号(2m^2-2m+5))