(X+(m-1))^2+(Y-2m)^2=-(5m^2-2m-8)-(m^2-2m+1)-4m^2
圆心为[-(m-1),2m]
因为求轨迹,设圆心坐标(x,y);
x=-m+1
y=2m
化简得y=2(1-X)
即2X+y-2=0
如果配方没错那就应该没错了