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设与X轴的二个交点坐标是:A(X1,0),B(X2,0),设x2>x1.与Y轴的交点是:C(0,Y1)又S(ABC)=3,即:S=1/2*|X2-X1|*|Y1|=3即:|X2-X1|*|Y1|=6因为X1,X2,Y1都是整数,且6=1*5=2*3所以有:(1)|X2-X1|=1,|Y1|=6又对称轴是x=2, 即x1+x2=2*2=4.所以,可得:x1=1.5,x2=2.5,与整数不符,舍.(2):|X2-X1|=6,|Y1|=1同上,x1+X2=4解得:X1=-1,X2=5,Y1=+1或-1所以,设解析式是y=a(x+1)(x-5)(0,1)代入解得a=-1/5,即解析式是:y=-1/5(x+... |
