已知:如圖,A(0,1)是y軸上一定點(diǎn),B是x軸上一動點(diǎn),以AB為邊,在∠OAB的外部作∠BAE=∠OAB,過B作BC⊥AB,交AE于點(diǎn)C.
(1)當(dāng)B點(diǎn)的橫坐標(biāo)為

時,求線段AC的長;
(2)當(dāng)點(diǎn)B在x軸上運(yùn)動時,設(shè)點(diǎn)C的縱、橫坐標(biāo)分別為y、x,試求y與x的函數(shù)關(guān)系式(當(dāng)點(diǎn)B運(yùn)動到O點(diǎn)時,點(diǎn)C也與O點(diǎn)重合);
(3)設(shè)過點(diǎn)P(0,-1)的直線l與(2)中所求函數(shù)的圖象有兩個公共點(diǎn)M
1(x
1,y
1)、M
2(x
2,y
2),且x
12+x
22-6(x
1+x
2)=8,求直線l的解析式.
