问题:
与y轴相切和半圆x 2+y 2=4(0≤x≤2)内切的动圆的圆心的轨迹是( )
A.y2="4(x-1)" (0<x≤1)
B.y2=-4(x-1)(0<x≤1)
C.y2="4(x+1)" (0<x≤1)
D.y2="-2(x-1)" (0<x≤1)
与y轴相切和半圆x 2+y 2=4(0≤x≤2)内切的动圆的圆心的轨迹是( )
A.y2="4(x-1)" (0<x≤1) |
B.y2=-4(x-1)(0<x≤1) |
C.y2="4(x+1)" (0<x≤1) |
D.y2="-2(x-1)" (0<x≤1) |
参考答案: