25.已知直線l
1:y=kx-4(k>0)分別與x軸,y軸交于A,B兩點(diǎn),直線l
2:y=-
x+4與y軸交于點(diǎn)C,與直線l
1交于點(diǎn)D.點(diǎn)P是線段OA上一動點(diǎn)(不與O,A重合),連接CP.
(1)如圖1,點(diǎn)D的橫坐標(biāo)為5.
?。笾本€l
1的函數(shù)表達(dá)式;
ⅱ.連接DP,若∠CPD=90°,求線段OP的長;
(2)如圖2,若OP=2,在線段CP上取點(diǎn)M,將線段MP繞點(diǎn)P順時(shí)針旋轉(zhuǎn)90°得到PN,點(diǎn)N恰好在直線l
1上,且AP=AN,求線段PM的長.