设y=a(x-1)²-4x=3,y=0代入得0=4a-4a=1∴y=(x-1)²-42.将该二次函数的图像向右平移b个单位,可使平移后所得图象经过坐标原点y=(x-1-b)²-4x=0,y=0代入得0=（1+b)²-41+b=±2b=1或-3(舍去）∴将该二次...