摘要:若动圆C与圆(x-2)2+y2=1外切.且和直线x+1=0相切.求动圆圆心C的轨迹E的方程.
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若圆C:x2+y2-ax+2y+1=0和圆x2+y2=1关于直线l1:x-y-1=0对称,动圆P与圆C相外切,且与直线l2:x=-1相切,则动圆P的圆心的轨迹方程是( )
A、x2+y2+x=0 | B、y2-2x+2y+3=0 | C、y2-6x+2y-2=0 | D、x2+y2+2x+2y=0 |