2011·广东揭阳·一模
1 . 在锐角
中,已知内角A、B、C所对的边分别为a、b、
c,且满足2sinB(2cos2
-1)=-
cos2B.
(1)求B的大小;
(2)如果
,求
的面积
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
c,且满足2sinB(2cos2
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c487a3ea4d0f807f1eea0d7c21ee92c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
(1)求B的大小;
(2)如果
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03837b3769eda7f0d3804cc5ad4a6d60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58195e8ee6f342c1641d9e88ff986f56.png)
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2012·广东汕头·模拟预测
2 . 如图,测量河对岸的塔高
时,可以选与塔底
在同一水平面内的两个测点
.现测得![](https://img.xkw.com/dksih/QBM/2012/6/3/1570877446799360/1570877452058624/STEM/8ee9637afe14440cb033887811e825e2.png)
,并在点
测得塔顶
的仰角为
, 求塔高
(精确到
,
)
![](https://img.xkw.com/dksih/QBM/2012/6/3/1570877446799360/1570877452058624/STEM/a3ac1104702b4050ba30a874cffa4c0f.png)
![](https://img.xkw.com/dksih/QBM/2012/6/3/1570877446799360/1570877452058624/STEM/8e501c0cc86244b0a67e47d6bb0f1277.png)
![](https://img.xkw.com/dksih/QBM/2012/6/3/1570877446799360/1570877452058624/STEM/1f540467ebe6495e9a4b68f7df5ab057.png)
![](https://img.xkw.com/dksih/QBM/2012/6/3/1570877446799360/1570877452058624/STEM/8ee9637afe14440cb033887811e825e2.png)
![](https://img.xkw.com/dksih/QBM/2012/6/3/1570877446799360/1570877452058624/STEM/4d88c50bbd7f45be9baded9956036a3d.png)
![](https://img.xkw.com/dksih/QBM/2012/6/3/1570877446799360/1570877452058624/STEM/8487614fa9024b1e87ca0cee28f69654.png)
![](https://img.xkw.com/dksih/QBM/2012/6/3/1570877446799360/1570877452058624/STEM/46e984db598e4bc6aae0613e654c7950.png)
![](https://img.xkw.com/dksih/QBM/2012/6/3/1570877446799360/1570877452058624/STEM/2de3d1dffdf549e19a6f7235bfd7c85d.png)
![](https://img.xkw.com/dksih/QBM/2012/6/3/1570877446799360/1570877452058624/STEM/a3ac1104702b4050ba30a874cffa4c0f.png)
![](https://img.xkw.com/dksih/QBM/2012/6/3/1570877446799360/1570877452058624/STEM/0a38a1bcc107442eb1a713e997f1207f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4084f37e52c1631113e0955a24281c53.png)
![](https://img.xkw.com/dksih/QBM/2012/6/3/1570877446799360/1570877452058624/STEM/cb31670cf7384d2db9755a830bb7819f.png)
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12-13高三上·福建福州·期末
名校
3 . 如图,在△ABC中,已知B
,AC=4
,D为BC边上一点.
(I)若AD=2,S△DAC=2
,求DC的长;
(Ⅱ)若AB=AD,试求△ADC的周长的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b3052da2d1bc23ddce31da1fbe42a6f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c3f8c3ba00c59e0634ed10fa85289de.png)
(I)若AD=2,S△DAC=2
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c3f8c3ba00c59e0634ed10fa85289de.png)
(Ⅱ)若AB=AD,试求△ADC的周长的最大值.
![](https://img.xkw.com/dksih/QBM/2012/2/20/1570753970348032/1570753975787520/STEM/c49df7c1c06b4e48bd90e13e84bb3eb5.png?resizew=181)
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2016-12-01更新
|
914次组卷
|
6卷引用:广东省清远市连南瑶族自治县大坪镇大坪中学2020-2021学年高二上学期期中数学试题
广东省清远市连南瑶族自治县大坪镇大坪中学2020-2021学年高二上学期期中数学试题(已下线)2012届福建省福州市高三第一学期期末质量检测理科数学(已下线)2012届浙江省温州市第二十二中高三迎一模复习试题文科数学四川省绵阳市第一中学2019-2020学年高一下学期入学考试数学试题(已下线)专题18 解三角形-2020年高考数学母题题源全揭秘(浙江专版)沪教版(2020) 一轮复习 堂堂清 第三单元 3.5 正弦定理,余弦定理(一)
10-11高二·广东中山·期中
4 . 如图所示,巡逻艇在A处测得某走私船在东偏南
方向距A处9海里的B处,正向南偏西
方向行驶,速度为20海里/小时,如果巡逻艇以航速28海里/小时,则应在什么方向用多少时间才能追上这艘走私艇?(
)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30c20e88a33043f4279fff360c81006e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1006d62fa5723dc36286b8f5494f993e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81bf1fe21f594f5a6a50fd12c721b4f4.png)
![](https://img.xkw.com/dksih/QBM/2011/12/20/1570626096218112/1570626101460992/STEM/53600e6ccf4a4fc1a4d14da9577d56b9.png?resizew=183)
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10-11高三·广东中山·阶段练习
5 . 在△ABC中,BC=2,AB+AC=3,中线AD的长为y,AB的长为x,
(1) 建立y与x的函数关系式,并指出其定义域.
(2) 求y的最小值,并指出x的值.
(1) 建立y与x的函数关系式,并指出其定义域.
(2) 求y的最小值,并指出x的值.
您最近一年使用:0次
11-12高二上·广东中山·期末
6 . 第四届中国国际航空航天博览会于2010年11月在珠海举行,如图是一架飞机在进行飞行表演.
![](https://img.xkw.com/dksih/QBM/2011/5/14/1570198657359872/1570198662848512/STEM/844a81f1-9df3-4f5e-9389-a6cc8c7c6eb1.png?resizew=235)
(1)若飞机在海拔
的高度飞行,从空中A处测出前下方海岛两侧海岸P、Q处的俯角分别是
和
,试计算这个海岛的宽度PQ;
(2)若两观测者甲、乙分别在海岛两侧海岸P、Q处同时测得飞机的仰角为
和
,他们估计P、Q两处距离大约为
,由此试估算出观测者甲(在P处)到飞机的直线距离.
![](https://img.xkw.com/dksih/QBM/2011/5/14/1570198657359872/1570198662848512/STEM/844a81f1-9df3-4f5e-9389-a6cc8c7c6eb1.png?resizew=235)
(1)若飞机在海拔
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09960e92ad5834fb6270f05e77e4ff2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6b86c22b670a8e9f3896f9e8883fbbb.png)
(2)若两观测者甲、乙分别在海岛两侧海岸P、Q处同时测得飞机的仰角为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6b86c22b670a8e9f3896f9e8883fbbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5980537b6c24aba358236446e7135daa.png)
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10-11高一下·广东佛山·阶段练习
名校
7 . 如图,为了解某海域海底构造,在海平面内一条直线上的A,B,C三点进行测量,已知
,
,于A处测得水深
,于B处测得水深
,于C处测得水深
,求
的余弦值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c46275d6b22c6662e62c542aa4d4af5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed50c3b12150fc25979dbba2d96598c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31fa2cd2f6ce52879b86b06338562dc3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96fb53ba72ce73f1d8c020e51d244805.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71b2d9ac78e9f998dd6e8d398d6aed8b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b3b0b11a80e8b107e55534d7fda9f2b.png)
![](https://img.xkw.com/dksih/QBM/2011/4/8/1570113272946688/1570113278418944/STEM/5508173de3e248e28c15bfd67ecf780e.png?resizew=171)
您最近一年使用:0次
2016-11-30更新
|
1391次组卷
|
6卷引用:2010-2011年广东省佛山一中高一下学期第一次月考数学试卷
11-12高一上·广东梅州·期末
8 . 如图,
、
两座城市相距100千米,现计划在这两座城市之间修筑一条高等级公路(即线段
).经测量,森林保护区中心
点在
城市的北偏东30°方向,
城市的北偏西45°方向上,已知森林保护区的范围在以
为圆心,50千米为半径的圆形区域内.请问:计划修筑的这条高等级公路会不会穿越保护区,为什么?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79dd200766db27fb90d6bd1992cf658.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://img.xkw.com/dksih/QBM/2011/2/25/1570013854703616/1570013860061184/STEM/2f9d840fd4bf48d48a369b0ce4548a7d.png?resizew=194)
您最近一年使用:0次
10-11高三上·山东泰安·期中
9 . 已知△
的内角
所对的边分别为
且
.
(1) 若
, 求
的值;
(2) 若△
的面积
求
的值.
![](https://img.xkw.com/dksih/QBM/2010/10/19/1569859095560192/1569859100876800/STEM/bbba856dce5746c69140036aaa440e99.png)
![](https://img.xkw.com/dksih/QBM/2010/10/19/1569859095560192/1569859100876800/STEM/3d5341fc347b46e188ac8f15b45612a5.png)
![](https://img.xkw.com/dksih/QBM/2010/10/19/1569859095560192/1569859100876800/STEM/42efa33573784bb88cdf412696ca1498.png)
![](https://img.xkw.com/dksih/QBM/2010/10/19/1569859095560192/1569859100876800/STEM/71fd517758454f67a7048a82862a7828.png)
(1) 若
![](https://img.xkw.com/dksih/QBM/2010/10/19/1569859095560192/1569859100876800/STEM/ba619d63cba04599923ec8a995901cd1.png)
![](https://img.xkw.com/dksih/QBM/2010/10/19/1569859095560192/1569859100876800/STEM/2a4938a779a8454a9d76352d3a6e9570.png)
(2) 若△
![](https://img.xkw.com/dksih/QBM/2010/10/19/1569859095560192/1569859100876800/STEM/bbba856dce5746c69140036aaa440e99.png)
![](https://img.xkw.com/dksih/QBM/2010/10/19/1569859095560192/1569859100876800/STEM/9f4a45287c624e33aea48529c3958dd5.png)
![](https://img.xkw.com/dksih/QBM/2010/10/19/1569859095560192/1569859100876800/STEM/6ce5dbe23229450a971a3ab2c4a36fe9.png)
您最近一年使用:0次
2016-11-30更新
|
633次组卷
|
11卷引用:2011-2012学年广东省惠阳一中高一期中考试文科数学试卷A卷
(已下线)2011-2012学年广东省惠阳一中高一期中考试文科数学试卷A卷(已下线)2012-2013学年广东陆丰碣石中学高二上期末考试文科数学试卷2015-2016学年广东省惠阳高级中学高二上学期期中考试理科数学试卷2015-2016学年广东省惠阳高级中学高二上学期期中考试文科数学试卷(已下线)2011届山东省宁阳一中高三上学期期中考试文科数学卷(已下线)2011-2012学年福建省安溪一中、养正中学高二上学期期末考试文科数学(已下线)2011-2012学年甘肃省金昌市第一中学高二期中考试文科数学试卷2014-2015学年海南省四校联考高一下学期期末考试数学试卷2015-2016学年广西武鸣县高中高二上段考文科数学试卷2015-2016学年广西武鸣县高中高二上段考理科数学试卷2016-2017学年湖南衡阳县四中高二理12月联赛数学试卷
9-10高一下·广东湛江·期末
10 . 在△
中,已知a、b、c分别是三内角
、
、
所对应的边长,且![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d692102a7fbbb5d5bfa42b1a4083a54b.png)
(Ⅰ)求角
的大小;
(Ⅱ)若
,试判断△ABC的形状并求角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d692102a7fbbb5d5bfa42b1a4083a54b.png)
(Ⅰ)求角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(Ⅱ)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c747944478053389224dffa40c6ba8b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
您最近一年使用:0次
2016-11-30更新
|
1086次组卷
|
3卷引用:2010年广东湛江市第二中学高一下学期期末考试数学卷