1 . 《九章算术》是中国古代第一部数学专著.《九章算术》中的“邪田”意为直角梯形,上、下底称为“畔”,高称为“正广”,非高腰边称为“邪”.如图所示,邪长为
,东畔长为
,在A处测得C,D两点处的俯角分别为49°和19°,则正广长约为______ .(注:
)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41322821ce31416fdac8dd6e0aa41c71.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dbff61fe9d4e93d7cc338489d1c99c40.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f37c15368bc89949ea2029bffbad988a.png)
![](https://img.xkw.com/dksih/QBM/2022/5/6/2973606468370432/2974203389198336/STEM/8176e977-5bda-4128-b834-4a94ff6c6299.png?resizew=243)
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2022-05-07更新
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745次组卷
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9卷引用:甘肃省金昌市永昌县第一高级中学2021-2022学年高二下学期期末数学(文)试题
名校
解题方法
2 . 如图,两条直路
与
相交于
点,且两条路所在直线夹角为
,甲、乙两人分别在
上的
两点,
,
.两人同时都以
的速度行走,甲沿
方向,乙沿
方向,问:
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/bbce06b9-01c6-47d3-b538-2f96a622ef1c.png?resizew=193)
(1)经过
小时后,两人距离是多少(表示为关于
的函数)?
(2)何时两人距离最近?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb780c38866c437ef52b2a9f7d508a0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a473e2b422c780bf7be36c856864995.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be6a6301878fed2a01413020b27310a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d03dcd681d12e6f678ac1c7234077393.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9133cab7c5d7ca61952c5e450c04e9bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8399812f1041d9c3bc9b59298093816.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ded8cda57d96761c878a88c390d8593.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c180184904f0eedbf65a102d6a27eb1b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2ee97c63a9188f12d894dd49e800d0b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/bbce06b9-01c6-47d3-b538-2f96a622ef1c.png?resizew=193)
(1)经过
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
(2)何时两人距离最近?
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