1 (x-2RcosQ)^2+(y-2RsinQ)^2=4R^2(cosQ)^2+4R^2(sinQ)^2-3R^2=R^2
圆心为(2RcosQ,2RsinQ)半径为R
2 圆心坐标x=2RcosQ
y=2RsinQ
其轨迹为x^2+y^2=4R^2
该圆必外切与x^2+y^2=R^2
而内切与x^2+y^2=9R^2
1 (x-2RcosQ)^2+(y-2RsinQ)^2=4R^2(cosQ)^2+4R^2(sinQ)^2-3R^2=R^2
圆心为(2RcosQ,2RsinQ)半径为R
2 圆心坐标x=2RcosQ
y=2RsinQ
其轨迹为x^2+y^2=4R^2
该圆必外切与x^2+y^2=R^2
而内切与x^2+y^2=9R^2