26.如圖,拋物線y=ax
2-2ax-3a(a>0)與x軸交于A,B兩點(diǎn)(點(diǎn)A在點(diǎn)B的左邊),與y軸交于點(diǎn)C,且OB=OC.
(1)求拋物線的解析式;
(2)如圖,若點(diǎn)P是線段BC(不與B,C重合)上一動(dòng)點(diǎn),過點(diǎn)P作x軸的垂線交拋物線于M點(diǎn),連接CM,當(dāng)△PCM和△ABC相似時(shí),求此時(shí)點(diǎn)P的坐標(biāo);
(3)若點(diǎn)P是直線BC(不與B,C重合)上一動(dòng)點(diǎn),過點(diǎn)P作x軸的垂線交拋物線于M點(diǎn),連接CM,將△PCM沿CM對折,如果點(diǎn)P的對應(yīng)點(diǎn)N恰好落在y軸上,求此時(shí)點(diǎn)P的坐標(biāo);