2.已知O為坐標(biāo)原點(diǎn),A(0,4),P是平面內(nèi)一動(dòng)點(diǎn),且
?
=0,記動(dòng)點(diǎn)P的軌跡為C.
(1)求C的方程.
(2)已知不經(jīng)過(guò)原點(diǎn)且斜率存在的直線(xiàn)l與C相交于M,N兩點(diǎn),且k
OM?k
ON=-3,試問(wèn)l是否經(jīng)過(guò)定點(diǎn)?若經(jīng)過(guò),求出該定點(diǎn)坐標(biāo);若不經(jīng)過(guò),說(shuō)明理由.