如圖,在直角坐標(biāo)系中,點(diǎn)A、B的坐標(biāo)分別為(1,4)和(3,0),點(diǎn)C是y軸上的一個(gè)動(dòng)點(diǎn),且A、B、C三點(diǎn)不在同一條直線上,當(dāng)△ABC的周長最小時(shí),點(diǎn)C的坐標(biāo)是( )
①(0,0);②(0,1);③(0,2);④(0,3).
![](http://hiphotos.baidu.com/zhidao/pic/item/9358d109b3de9c8280b89f086f81800a18d84353.jpg)
A. ①
B. ②
C. ③
D. ④
![](http://hiphotos.baidu.com/zhidao/pic/item/cdbf6c81800a19d8eaf7e28230fa828ba71e4644.jpg)
作B點(diǎn)關(guān)于y軸對(duì)稱點(diǎn)B′點(diǎn),連接AB′,交y軸于點(diǎn)C′,
此時(shí)△ABC的周長最小,
∵點(diǎn)A、B的坐標(biāo)分別為(1,4)和(3,0),
∴B′點(diǎn)坐標(biāo)為:(-3,0),AE=4,
則B′E=4,即B′E=AE,
∵C′O∥AE,
∴B′O=C′O=3,
∴點(diǎn)C′的坐標(biāo)是(0,3),此時(shí)△ABC的周長最小.
故選:D.