已知抛物线Y=X^2+(1-2a)X+a^2 {其中a不等于0}与X轴交于A.B两点.与Y轴交于点C,且OA+OB=OC-2,求a的值.设与X轴的二个交点坐标是：（ x1,0),(x2,0)则有：x1+x2=-(1-2a)=2a-1,x1x2=a^2|OA|+|OB|=|x2-x1|又：(x2-x1)^2=(x1...