1 . 如图,在正方体
中,
,
,
分别是棱
,
,
的中点,又
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/19/5885aa87-0d8c-4524-b6f1-11d10e4ae823.png?resizew=221)
(1)求证:平面
平面
;
(2)求直线
与
所成角的余弦值;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/19/5885aa87-0d8c-4524-b6f1-11d10e4ae823.png?resizew=221)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f79058a6f1268b5b1af757ccecff683.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ebf7be76eb49f41bed85431705597b9.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13cf3a313649d7b92f28dd9fb8c27e41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
您最近一年使用:0次
2022-08-11更新
|
377次组卷
|
2卷引用:江苏省南京市田家炳高级中学2022-2023学年高二上学期10月月考数学试题
名校
解题方法
2 . 在
,角A,B,C所对应的边是a,b,c,满足
,且
.
(1)求证:
;
(2)若C为钝角,D为边
上的点,满足
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c78a9c0156e9dddaefb3b91fa146a4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f086db5abeb9d3da702d22d1d249818f.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50fe3ff195737d076e69a6a30e363f66.png)
(2)若C为钝角,D为边
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f9ecec6c3d9ae212b967e61be50ebf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c2abe5da7ee1a2ff3ca5dec7a2d04dc.png)
您最近一年使用:0次
2023-02-10更新
|
1677次组卷
|
4卷引用:江苏省南京市第二十九中学2022-2023学年高三下学期4月月考数学试题
名校
3 . 如图所示的矩形
中,
分别为线段
上的动点.
为靠近
的三等分点,
为
的中点,且
,求
的值;
(2)若
是边长为1的正三角形.
(i)令
、
、
的面积分别为
,
,
,证明:
;
(ii)求矩形
面积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/374fe9986ebbc986fc422e514ab93a51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c562ffebf701e6d812eed6fc898fb42b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b88584cf1df43e28d03592c7998b1653.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72cb97395ebc5ee1b212afb7a97b985c.png)
(i)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13668f033d00acfc366f7e47949c4462.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d85bcd207e761df740d87a6acb81bf7a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e097c8d4c948de063796bd19f85b3a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e0bd63f55069a3bc870915010b39225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6899bf9cadae2ccdb14cbc87d4f280ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/485fd8aa254b523bef30560500ccaf41.png)
(ii)求矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
您最近一年使用:0次
2023-04-19更新
|
1040次组卷
|
4卷引用:江苏省南京市协同体七校2022-2023学年高一下学期期中联考数学试题
江苏省南京市协同体七校2022-2023学年高一下学期期中联考数学试题广东省惠州大亚湾经济技术开发区第一中学2023-2024学年高二上学期第一次月考数学试题(已下线)模块四 高一下期中重组篇(江苏)(已下线)专题4 考前优质试题精选练(4)(北师大版高一期中)
名校
解题方法
4 . 在
中,
均为锐角.
(1)若
,求证:
是直角三角形;
(2)若
,求证:
是直角三角形;
(3)若
,那么
还一定是直角三角形吗?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adbbcd81fe3cadffa209c49edb55c424.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9ba45dae06449cb6c920ae62dfe981.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ed246ac62ff6267137ec814220d1fe6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
您最近一年使用:0次
名校
解题方法
5 . 记
的内角A,B,C的对边分别为a,b,c,已知
.
(1)证明:
;
(2)若
的面积最大值为
,求c.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d613defbe6e447433fcc072829eb0785.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37238084e3ac028b0378bff6ab377c8b.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2967337e3fcb228dded64ab0c41a17e0.png)
您最近一年使用:0次
21-22高一下·江苏南通·期中
名校
解题方法
6 . 如图,在正方体
中,
分别为
,AB中点.
![](https://img.xkw.com/dksih/QBM/2022/5/16/2980610696609792/2981280855351296/STEM/371f4d35-b257-4fdc-826f-d08e32ba8779.png?resizew=187)
(1)求证:
平面
;
(2)求异面直线EF与
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e539f26ed5e0b20ff7220559324869a4.png)
![](https://img.xkw.com/dksih/QBM/2022/5/16/2980610696609792/2981280855351296/STEM/371f4d35-b257-4fdc-826f-d08e32ba8779.png?resizew=187)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06222ee533c2484ab25321a6abbf98cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ebb05874eb3353d754af24c9974273e.png)
(2)求异面直线EF与
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83c09eec4e14a861af83d7828797d176.png)
您最近一年使用:0次
2022-05-17更新
|
1780次组卷
|
4卷引用:江苏省南京市金陵中学河西分校2022-2023学年高二上学期期初调研测试数学试题
江苏省南京市金陵中学河西分校2022-2023学年高二上学期期初调研测试数学试题(已下线)江苏省南通市如皋市2021-2022学年高一下学期教学质量调研(二)数学试题江苏省沐阳县修远中学2021-2022学年高一下学期教学质量调研数学试题(二)广西玉林市博白县中学2022-2023学年高一下学期4月联考数学试题
名校
解题方法
7 . 在
中,内角A,B,C的对边分别为a,b,c.已知
,
.
(1)求证:
是直角三角形;
(2)已知
,
,点P,Q是边AC上的两个动点(P,Q不重合),记
.
①当
时,设
的面积为
,求
的最小值;
②记
,
.问:是否存在实常数
和
,对于所有满足题意的
,
,都有
成立?若存在,求出
和
的值;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f325826267a4d242f3b3ab335a83796b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e899c486dc49e560fc4aca05e16835b7.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96fbed3c855b8d52c669712a4410fd39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7fa79a550591eb9e1bd07bced3a08fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78f68ade9c228169668792516571e28a.png)
①当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78a40d2cf43fce0c99dff3470d554eb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c495b8fd7f7bb21c177c9d50fbf6919.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
②记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12c47acbb0d7d46a8de00fc59849feaf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4049622421974f1501f377f0f4f4f9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](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/faac624f25ebbba44bf8f2c4a84791cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
您最近一年使用:0次
2022-04-26更新
|
1274次组卷
|
5卷引用:江苏省南京师范大学附属中学2021-2022学年高一下学期期中数学试题
江苏省南京师范大学附属中学2021-2022学年高一下学期期中数学试题(已下线)专题14解三角形-2022年新高三数学暑假自学课精讲精练(已下线)专题07 解三角形(讲义)-2湖北省十堰市丹江口市第一中学2021-2022学年高一下学期期末数学试题江苏省无锡市南菁高级中学2023-2024学年高一创新班上学期10月月考数学试题
名校
解题方法
8 . 已知直线
.
(1)证明:直线
过定点;
(2)若直线不经过第四象限,求
的取值范围;
(3)若直线
交
轴负半轴于
,交
轴正半轴于
,
的面积为
,求
的最小值并求此时直线
的方程.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81c1606c63fa3555bd2dc2affcd92525.png)
(1)证明:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
(2)若直线不经过第四象限,求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
(3)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/866b81a8384cce4f24867baca2e6820c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
您最近一年使用:0次
2022-12-10更新
|
790次组卷
|
5卷引用:江苏省南京市天印高级中学2022-2023学年高二上学期11月月考数学试题
江苏省南京市天印高级中学2022-2023学年高二上学期11月月考数学试题(已下线)专题08 选择性必修第一册综合练习(已下线)2.2 直线的方程(精练)-2023-2024学年高二数学《一隅三反》系列(人教A版2019选择性必修第一册)(已下线)1.2 直线的方程(八大题型)-【帮课堂】2023-2024学年高二数学同步学与练(苏教版2019选择性必修第一册)山东省泰安市泰山区泰安第二中学2023-2024学年高二上学期10月月考数学试题
名校
解题方法
9 . 如图,在
中,D是
边上的一点,
,
.
![](https://img.xkw.com/dksih/QBM/2023/2/27/3183868663463936/3185098722492416/STEM/ed24d0e719c04be38aeb4d61e9ba4f1a.png?resizew=202)
(1)证明:
;
(2)若D为靠近B的三等分点,
,
,
,
为钝角,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8825684b8a4c71389727f390d0b653ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8ef0fe903cbb848b6215ad5a772e3f0.png)
![](https://img.xkw.com/dksih/QBM/2023/2/27/3183868663463936/3185098722492416/STEM/ed24d0e719c04be38aeb4d61e9ba4f1a.png?resizew=202)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be274bb6d78aaa718ca6bba329cdd54c.png)
(2)若D为靠近B的三等分点,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b8b709a173120436dac669c74b927d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b4ac154eb73d2fe8d683961aa63ace8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbce11aa19b8bd2bf6ee5a834e005de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5c141b06b158e0cdef08fcda3ea44a7.png)
您最近一年使用:0次
2023-03-01更新
|
2928次组卷
|
6卷引用:江苏省南京市江浦高级中学2023届高三下学期3月月考数学试题
江苏省南京市江浦高级中学2023届高三下学期3月月考数学试题广东省汕头市2023届高三第一次模拟数学试题(已下线)广东省汕头市2023届高三第一次模拟数学试题变式题17-22专题10解三角形青海省西宁市2023届高三二模理科数学试题湖南省岳阳市岳州中学2022-2023学年高一下学期3月月考数学试题
解题方法
10 . 在
中,角A,B,C的对边分别为a,b,c,已知
,
,
.
(1)求证:
;
(2)若
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58f67700a8a3d1438d9a249a9e30c0da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0499f3c390ad21ba9a7a6a97afc6ac78.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/014a82692e31ac1980b50100c919254c.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02746ec8e4220d8b4a174d5e9a711ed2.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d8abff30fc308565d3a23dd2739e5c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79b01adc561735ff5be9bb97266918f2.png)
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