Question

圓(x-1)²+(y-3)²=1關(guān)于直線2x+y+5=0對(duì)稱的圓的方程是(　　)

A．(x+7)2+(y+1)2=1

B．(x+7)2+(y+2)2=1

C．(x+6)2+(y+1)2=1

D．(x+6)2+(y+2)2=1

Answer 1

A

因?yàn)閳A心(1,3)關(guān)于直線2x+y+5=0的對(duì)稱點(diǎn)為(-7,-1),
所以所求圓的方程為(x+7)²+(y+1)²=1.