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/2023/4/29/77b0b34b-074a-432e-b085-84b49b9fd17d.png?resizew=213)
(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2万元,种植经济作物的成本为每平方百米1万元,新建道路
的成本为每百米1万元,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/7555d7708fbcceafdca92f950b96834c.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/2023/4/29/77b0b34b-074a-432e-b085-84b49b9fd17d.png?resizew=213)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e772672c590dc0ff3fd45532ab5ee54d.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)
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解题方法
2 . 如图所示,某海滨养殖场有一块可用水域,该养殖场用隔离网
把该水域分为两个部分,其中
百米,现计划过
处再修建一条直线型隔离网,其端点分别在
上,记为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/24/202a1552-3a79-42a6-a8a6-d5cf97a1412b.png?resizew=170)
(1)若要使得所围区域
面积不大于
平方百米,求
的取值范围:
(2)若要在
区域内养殖鱼类甲,
区域内养殖鱼类乙,已知鱼类甲的养殖成本是
万元/平方百米,鱼类乙的养殖成本是
万元/平方百米.试确定
的值,使得养殖成本最小,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abd13974aebe38eb2a1d744a01ea5aa5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d5d2552cd2dd87c8191f5473d439bf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f65dbed884e2248ec075655c684aa7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/24/202a1552-3a79-42a6-a8a6-d5cf97a1412b.png?resizew=170)
(1)若要使得所围区域
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6765a87bcc2b6d44aabdee9af73e6cd2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adbd3e8cf8325999cde03adf845d3dd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.png)
(2)若要在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f6bc20cf084f78b63b9990cf4fa769b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31b6f4f9b0fe1c073ae2e085adc26fcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.png)
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2020高三·江苏·专题练习
解题方法
3 . 如图,某公园内有两条道路
,
,现计划在
上选择一点
,新建道路
,并把
所在的区域改造成绿化区域.已知
,
.
(1)若绿化区域
的面积为
,求道路
的长度;
(2)若绿化区域
改造成本为10万元
,新建道路
成本为10万元
.设
,当
为何值时,该计划所需总费用最小?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/954d2fd2aecd31ff67d975bc8981023a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d96b98fa3d42c6110aacdd8b40cc878.png)
(1)若绿化区域
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a20c0350438830b350bb4a230047f34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
(2)若绿化区域
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f73840c256b07fc8619ca3864ab6cda0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c1feb40df85e8deb28601e2bfec896f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83807e0aa1085d518688730cbd0a6178.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://img.xkw.com/dksih/QBM/2020/1/16/2378537747431424/2379990478848000/STEM/2a3a8405912a4eacb88d1c32a8c4de13.png?resizew=134)
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