若方程x^2+y^2-2(m+3)x+2(1-4m^2)y+16m^4+9=0表示圆,则m的取值范围是

问题描述:

若方程x^2+y^2-2(m+3)x+2(1-4m^2)y+16m^4+9=0表示圆,则m的取值范围是

x^2+y^2-2(m+3)x+2(1-4m^2)y+16m^4+9=0
[x-(m+3)]^2-(m+3)^2+[y+(1-4m^2)]^2-(1-4m^2)^2+16m^4+9=0
[x-(m+3)]^2+[y+(1-4m^2)]^2=-7m^2+6m+1
-7m^2+6m+1>=0
7m^2-6m-1