某公路的同一侧有a,b,c三个村庄，要在公路边建一货栈d向a,b,c三个村庄运送农用物资，

来源：百度知道 编辑：UC知道 时间：2024/05/09 13:01:00
路线是d→a→b→c→d或d→c→b→a→d，
1）试问在公路边是否存在一点d,使送货路程最短？（把公路边近似看做公路上）
2）将a(1,2)b(2,4)c(4,1)放在平面直角坐标系中，把x轴建立在公路上，试求出点d在该坐标系上的坐标
要有详细过程，非常感谢
要有计算过程

这道题学过~~就是画坐标轴~~画出来就一目了然了。

1.做A以x轴的对称点A1(1,-2)
连接A1C交x轴于D
D为所求
2偶没带纸和笔~~不好意思~~~算不出来~

印象中好像是这样啦~~~不太肯定~

做 A以x轴的 对称 点A1(1,-2)
连 接A1C交x轴 于D
D 为所求
好象里面有点问题吧?
公式好象是另外一个

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1.A做x轴的对称点A1(0,-2)
连接A1C交x轴于D
D为所求
2.D(2.5,0)

1.A做x轴的对称点A1(0,-2)
连接A1C交x轴于D
D为所求
2.D(2.5,0)