27.如圖,在平面直角坐標(biāo)系中,點(diǎn)O為坐標(biāo)原點(diǎn),△ABC的頂點(diǎn)A在y軸上,點(diǎn)B、C在x軸上,AC=3
,∠ACB=45°,BC=4.
(1)求點(diǎn)B的坐標(biāo);
(2)過(guò)點(diǎn)A作射線AP∥x軸,點(diǎn)P在第一象限內(nèi),連接BP,過(guò)點(diǎn)C作CQ⊥BP交y軸于點(diǎn)Q,垂足為點(diǎn)E,設(shè)點(diǎn)P的橫坐標(biāo)為t,線段OQ的長(zhǎng)為d,求d與t的關(guān)系式(不用寫t的取值范圍);
(3)在(2)的條件下,線段CQ交AP于點(diǎn)F,若PE=QF,求點(diǎn)P的坐標(biāo).