图象过原点(0,0),则c=0,设二次函数解析式为y=ax²+bx,图象过(-1,1).则1=a-b; X=-b/2a=1或-1.由1=a-b和-b/2a=1得:a=1/3,b=-2/3;由1=a-b和-b/2a=-1得:a=-1,b=-2.故解析式为y=(1/3)x²-(2/3)x或-x²-2x....