(1)∵抛物线y=x2+bx+c与y轴交于点C(0,3),∴c=3.?∴y=x2+bx+3.又∵抛物线y=x2+bx+c与x轴交于点A(1,0),∴b=-4.?∴y=x2-4x+3.(2)点P的坐标为(5,8)或(-1,8).