顶点坐标是(1.16),有X=-B/2A=1,B=-2A.Y=(4AC-B^2)/4A=16,B^2-4AC=-4*16A.解得,C=16+4A.|X2-X1|=AB=8,X1^2+X2^2-2X1*X2=64,(X1+X2)^2-4X1*X2=64.X1+X2=-B/A,X1*X2=C/A.(-B/A)^2-4C/A=64,B^2-4AC=64A^2,B^2-4AC=-4*16A,-4*16A=64A^2,(A≠0,)A=-1.B=-2A=2.C=16+4A=16-4=12.抛物线的表达式为:Y=-X^2+2X+12....
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