26.如圖1,拋物線y=-x
2+bx+3與x軸交于A,B兩點(diǎn),過A點(diǎn)的直線L:y=-x-1與y軸交于點(diǎn)C,點(diǎn)P為直線L上方的拋物線上一動(dòng)點(diǎn).
(1)求拋物線的解析式;
(2)若過點(diǎn)C的直線交線段AB于點(diǎn)M,且S
△ACM:S
△BCM=3:1,求直線CM的解析式;
(3)如圖2,過P點(diǎn)作PE∥y軸交直線AC于點(diǎn)E,連接AP.當(dāng)△APE為直角三角形時(shí),求點(diǎn)P的坐標(biāo).