1 . 在△ABC中,角A,B,C的对边分别为a,b,c,并且sin2
=
.
(1)试判断△ABC的形状并加以证明;
(2)当c=1时,求△ABC周长的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb29929391f974b99b4264dd4c9a7786.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17c7017c013e5fd52e194f4b99ee10b9.png)
(1)试判断△ABC的形状并加以证明;
(2)当c=1时,求△ABC周长的最大值.
您最近一年使用:0次
2017-11-28更新
|
600次组卷
|
5卷引用:河南省某重点高中2017-2018学年上学期高二期中考试数学(文)试题
河南省某重点高中2017-2018学年上学期高二期中考试数学(文)试题安徽省全椒中学2017-2018学年高一第一学期期中考试数学试题(已下线)2018年12月30日 《每日一题》(理数)人教必修5+选修2-1(高二上期末复习)-每周一测(已下线)第1章 章末检测-2018-2019版数学创新设计课堂讲义同步系列(苏教版必修5)(已下线)2019年12月29日《每日一题》必修5+选修2-1理数-每周一测
名校
解题方法
2 . 如图:
为
所在平面外一点,
,
,
,
平面
于
.求证:
![](https://img.xkw.com/dksih/QBM/2017/5/21/1691844970971136/1691942131220480/STEM/7ab23720474f4619b12f87597b624023.png?resizew=222)
(1)
是
的垂心;
(2)
为锐角三角形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83640592853a53872d7af69c0cffc1bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a916d31a199e250556fb7478d9f57f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b71c3c9fe52ad7ab87da571a72c4eea2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b17622ea6f6f5afd1ad817a557e5889d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://img.xkw.com/dksih/QBM/2017/5/21/1691844970971136/1691942131220480/STEM/7ab23720474f4619b12f87597b624023.png?resizew=222)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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11-12高三下·上海·开学考试
名校
3 . 已知
中,三个内角
、
、
的对边分别是
、
、
,其中
,且
.
(1)求证:
是直角三角形;
(2)设圆
过
、
、
三点,点
位于劣弧上
,
.求四边形
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.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/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6d39e8c6fc9149d6290c493a65bdc53.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3aa171ccbdd48673be1713e67fb130e7.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)设圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.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/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/667349d99185bb045030b733352ff7fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42e12bfde565540f059dd27ea47dfaa7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b027ed57b9c6f24e27ec0ae282c76efa.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/10/65ed77cf-6ea3-4443-83da-cd615194c0f9.png?resizew=206)
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2017-04-21更新
|
421次组卷
|
3卷引用:2016-2017学年湖北省重点高中联考协作体高一下学期期中考试数学试卷
4 . 在
中,
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd936a2405709574af0a73543d94ad9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f28dd9b93598b2e23fe49e58b258dca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81fdecc54535c26dc76ffffe49a23996.png)
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2011·河北唐山·一模
名校
5 . △ABC中,角A,B,C对边的边长分别是a,b,c,且a(cosB+cosC)=b+c.
(1)求证:A
;
(2)若△ABC外接圆半径为1,求△ABC周长的取值范围.
(1)求证:A
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c72add9c1c236c3cd8f0be037f200798.png)
(2)若△ABC外接圆半径为1,求△ABC周长的取值范围.
您最近一年使用:0次
2016-11-30更新
|
1076次组卷
|
3卷引用:上海市光明中学2015-2016学年高一下学期期中数学试题
13-14高三上·四川成都·期中
解题方法
6 .
中,
,
.
(1)求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db36e0ad412438cb5d6305f1e20e73a4.png)
(2)若a、b、c分别是角A、B、C的对边,
,求c和
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9f23dd25bdfba2a782d12f07b0f1384.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/455a2989f11aba660eb0ee2a0a2624c9.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db36e0ad412438cb5d6305f1e20e73a4.png)
(2)若a、b、c分别是角A、B、C的对边,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e258ab9e600435b37465092243d99f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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7 . 如右图,在
中,设
,
,点
在
边上.
![](https://img.xkw.com/dksih/QBM/2016/6/23/1572816948092928/1572816954335232/STEM/c5115a9784104d09bc8ed4761c303ac5.png)
(I)若
为
边中点,求证:
;
(II)若
,求证:
.
![](https://img.xkw.com/dksih/QBM/2016/6/23/1572816948092928/1572816954335232/STEM/5e506f560baf4848842438ec7b37fd23.png)
![](https://img.xkw.com/dksih/QBM/2016/6/23/1572816948092928/1572816954335232/STEM/7906e61f0ef640d4ab88fc6560fd635a.png)
![](https://img.xkw.com/dksih/QBM/2016/6/23/1572816948092928/1572816954335232/STEM/043859e7cffc4f08b32bbdaaf9c52d01.png)
![](https://img.xkw.com/dksih/QBM/2016/6/23/1572816948092928/1572816954335232/STEM/ce184601fa744b629ec83bd55b70603f.png)
![](https://img.xkw.com/dksih/QBM/2016/6/23/1572816948092928/1572816954335232/STEM/28919d6cdcd94714949bf0cf43c9868d.png)
![](https://img.xkw.com/dksih/QBM/2016/6/23/1572816948092928/1572816954335232/STEM/c5115a9784104d09bc8ed4761c303ac5.png)
(I)若
![](https://img.xkw.com/dksih/QBM/2016/6/23/1572816948092928/1572816954335232/STEM/ce184601fa744b629ec83bd55b70603f.png)
![](https://img.xkw.com/dksih/QBM/2016/6/23/1572816948092928/1572816954335232/STEM/28919d6cdcd94714949bf0cf43c9868d.png)
![](https://img.xkw.com/dksih/QBM/2016/6/23/1572816948092928/1572816954335232/STEM/2f7418c3bd8544f7811868759d26e956.png)
(II)若
![](https://img.xkw.com/dksih/QBM/2016/6/23/1572816948092928/1572816954335232/STEM/d1103989172743399d5e5cc9edae737e.png)
![](https://img.xkw.com/dksih/QBM/2016/6/23/1572816948092928/1572816954335232/STEM/9056b73698a44cc8a4f0ee69edadbe5b.png)
您最近一年使用:0次
8 . 如图,在山脚A测得山顶P的仰角为
,沿倾斜角为
的斜坡向上走a米到B,在B处测得山顶P的仰角为
.
![](https://img.xkw.com/dksih/QBM/2011/5/27/1570225116495872/1570225121837056/STEM/da398483-138a-4cce-a182-0501f740a04b.png?resizew=263)
(1)求PA长度;
(2)证明:山高
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f435efcc7869eec21bdba1ed81dc3f5.png)
![](https://img.xkw.com/dksih/QBM/2011/5/27/1570225116495872/1570225121837056/STEM/da398483-138a-4cce-a182-0501f740a04b.png?resizew=263)
(1)求PA长度;
(2)证明:山高
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f46dc8fc447dbaebfdb6b73f51edfe61.png)
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9 . 已知
分别为
三个内角
的对边,
.
(1)求
;
(2)若
,
的面积为
,证明:
是正三角形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bbf5887ebf0a2fb425dc594bb983585.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f2333da32638ec636fa1e69e750ca4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3edd51c782333e04862704165622ad68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d01d2956b453f7a29b4221cee240dbc.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e258ab9e600435b37465092243d99f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f2333da32638ec636fa1e69e750ca4a.png)
![](https://img.xkw.com/dksih/QBM/2016/9/5/1572998259163136/1572998264791040/STEM/5a025e3e091149dcb30b35aa15f5a92e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f2333da32638ec636fa1e69e750ca4a.png)
您最近一年使用:0次