解题方法
1 . 如图,某生态农庄内有一三角形区域
,
,
百米,
百米.现要修一条直道
(宽度忽略不计),点
在道路
上(异于
,
两点).
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/29/0dc8c034-6761-471f-9817-2d21b91c6f0a.png?resizew=168)
(1)若
,求
的长度;
(2)现计划在
区域内种植观赏植物,在
区域内种植经济作物.已知种植观赏植物的成本为每平方百米4万元,种植经济作物的成本为每平方百米2万元,新建道路
的成本为每百米2万元,求三项费用总和的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6610676353016a9f7235d306b731c1e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ffc2817fa590affb5a760a25dc65308.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/29/0dc8c034-6761-471f-9817-2d21b91c6f0a.png?resizew=168)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a311738db3fc5431d14a0942542a62e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
(2)现计划在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ac451db3443cabb204f96c31fd4a02e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
您最近一年使用:0次
名校
2 . 为丰富农村业余文化生活,决定在A,B,N三个村子的中间地带建造文化中心.通过测量,发现三个村子分别位于矩形ABCD的两个顶点A,B和以边AB的中心M为圆心,以MC长为半径的圆弧的中心N处,且AB=8km,BC=
km.经协商,文化服务中心拟建在与A,B等距离的O处,并建造三条道路AO,BO,NO与各村通达.若道路建设成本AO,BO段为每公里
万元,NO段为每公里a万元,建设总费用为
万元.
![](https://img.xkw.com/dksih/QBM/2018/10/11/2051196398305280/2055731747856384/STEM/3d6b47d009ba4708b0a5bca4bdc6e7d3.png?resizew=158)
(1)若三条道路建设的费用相同,求该文化中心离N村的距离;
(2)若建设总费用最少,求该文化中心离N村的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e2031d209711b058f3d278ede3c1d33.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/827bec361fa9658bc190b57633f2b5aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/595044a7750ab4f84519041979c3d780.png)
![](https://img.xkw.com/dksih/QBM/2018/10/11/2051196398305280/2055731747856384/STEM/3d6b47d009ba4708b0a5bca4bdc6e7d3.png?resizew=158)
(1)若三条道路建设的费用相同,求该文化中心离N村的距离;
(2)若建设总费用最少,求该文化中心离N村的距离.
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