顶点坐标是（-1，-4)所以设y=a(x+1)^2-4a(x+1)^2-4=0ax^2+2ax+a-4=0x1+x2=-2x1x2=(a-4)/ax1^2+x2^2=10(x1+x2)^2-2x1x2=104-2(a-4)/a=10a=1所以函数解析式为y=(x+1)^2-4=x^2+2x-3
