题目内容
若直线mx+2ny-4=0(m,n∈R)将圆x2+y2-4x-2y-4=0分成两段相等的弧,则m+n等于
A.-2
B.-1
C.1
D.2
若直线mx+2ny-4=0(m,n∈R)始终平分圆x2+y2-4x-2y-4=0的周长,则m·n的取值范围是
(0,1]
(0,1)
(-∞,1]
(-∞,1)
若直线mx+2ny-4=0(m、n∈R,n≠m)始终平分圆x2+y2-4x-2y-4=0的周长,则mn的取值范围是( )
A.(0,1) B.(0,-1)
C.(-∞,1) D.(-∞,-1)
若直线mx+2ny-4=0始终平分圆x2+y2-4x-2y-4=0的周长,则mn的取值范围是( )
A.(0,1) B.(0,1]
C.(-∞,1) D.(-∞,1]