动圆x方+y方-(4m+2)x-2my+4m+1=0配方得 [x-(2m+1)]²+(y-m)²=(2m+1)²+m²-(4m+1)∴ [x-(2m+1)]²+(y-m)²=5m²,∴ m≠0设圆心为(x,y)则 x=2m+1,y=m 消去m,得到 x=2y+1 且y≠0∴ 圆心...