准线x=-1/2
圆心(a,b)
圆心到切线距离等于半径
所以到准线距离等于到x轴距离
即a-(-1/2)=|b|
a+1/2=|b|
a=|b|-1/2
圆心在抛物线Y^2=2X上
|b|^2=2a
(a+1/2)^2=2a
a^2-a+1/4=0
(a-1/2)^2=0
a=1/2,|b|=1
r^2=|b|^2=1
所以(x-1/2)^2+(y-1)^2=1和(x-1/2)^2+(y+1)^2=1