6.圓(x-3)2+(y+4)2=2關(guān)于直線x+y=0的對(duì)稱圓的標(biāo)準(zhǔn)方程是( B )A.(x+3)2+(y-4)2=2 B.(x-4)2+(y+3)2=2C.(x+4)2+(y-3)=2 D.(x-3)2+(y-4)2=2祥解,謝謝

熱心網(wǎng)友

對(duì)稱圓的半徑不變，圓心為原圓心的對(duì)稱點(diǎn)；所以對(duì)稱圓的圓心為(4,-3),半徑為根號(hào)2；即圓方程為(x-4)^2+(y+3)^2=2;

熱心網(wǎng)友

6.圓(x-3)^2+(y+4)^2=2關(guān)于直線x+y=0的對(duì)稱圓的標(biāo)準(zhǔn)方程是( B )A.(x+3)^2+(y-4)^2=2 B.(x-4)^2+(y+3)^2=2C.(x+4)^2+(y-3)^2=2 D.(x-3)^2+(y-4)^2=2設(shè)圓(x-3)^2+(y+4)^2=2上的點(diǎn)為P(x′,y′），對(duì)稱圓上的點(diǎn)為Q（x,y)因?yàn)镻、Q關(guān)于y=-x對(duì)稱，所以x′＝-y ,y′＝-x　，把x′＝-y ,y′＝-x　代入(x-3)^2+(y+4)^2=2中得：(x-4)^2+(y+3)^2=2 選　B