题目内容
A.x2+y2=4
B.x2+y2=4(x≠±2)
C.x2+y2=4(x≠±1)
D.x2+y2=1(x≠±1)
A.x2+y2=4
B.x2+y2=4(x≠±2)
C.x2+y2=4(x≠±1)
D.x2+y2=1(x≠±1)
A.x2+y2=4 B.x2+y2=4(x≠±2)
C.x2+y2=4(x≠±1) D.x2+y2=1(x≠±1)