∵顶点P的坐标为（1,-2),设抛物线为y=a(x-1)²-2.则抛物线的对称轴为：x=1∵y=a(x-1)²-2过点（0,-1）,∴a=1∴抛物线y=a(x-1)²-2开口向上∵抛物线的对称轴为：x=1∴当x≤1时,函数y=a(x-1)²-2随自...