1 . 如图,在三棱台
中,H在AC边上,平面
平面
,
,
,
,
,
.
;
(2)若
且
的面积为
.求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/986ba572d8373df48c996f8c8611498c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/471d953c1e7ff54f688b5d4ec5785e9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa18c2a78c400c80a5760743f31771c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a309d190802e8a90b421174da5cfc72a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e673ef2d48215ca84a48377f17d6df00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f656e1d1f68954e5f06de8958f6a9310.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8439d059d08e4ee524b234f3f490aaa8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c672f693a7e75a7bae4936dcb1920430.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd2e870c95b1ed54b281f93e683578bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2ca820a456491348e72587e4fe10bc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cae70b8a9d2d2e96dea62c00ced04b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd284f76d9f5769bc189508ce2572b.png)
您最近一年使用:0次
2024·全国·模拟预测
名校
2 . 美国数学史家、穆伦堡学院名誉数学教授威廉・邓纳姆在1994年出版的The Mathematical Universe一书中写道:“相比之下,数学家达到的终极优雅是所谓的‘无言的证明’,在这样的证明中一个极好的令人信服的图示就传达了证明,甚至不需要任何解释.很难比它更优雅了.”如图所示正是数学家所达到的“终极优雅”,该图(
为矩形)完美地展示并证明了正弦和余弦的二倍角公式,则可推导出的正确选项为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2024-04-28更新
|
257次组卷
|
3卷引用:甘肃省白银市靖远县第一中学2024届高三下学期模拟预测数学试题
3 . 如图,在四棱锥
中,底面
为等腰梯形,
,
,
平面
,
,点
为线段
中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/1/a9f935db-30a7-4ee1-b8c9-ef0bdf23f907.png?resizew=156)
(1)求证:
平面
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f571396be1aa4a8914a66f7d7abd6381.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6e0b64d25ddd18454f88e40c45d7d8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10c83f8945042b9c8fb2fbdac9308d62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39c049bbf873a6af116712840484b98f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/defa5b53043ae802bb1af7d14374406d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/1/a9f935db-30a7-4ee1-b8c9-ef0bdf23f907.png?resizew=156)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9c9cfa597b444b5c9dbae7a825a695.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/735056c174e8dd7906257a2a50a962a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5000fea066102e62cf2128ccbbd2b3e3.png)
您最近一年使用:0次
2023-07-31更新
|
551次组卷
|
2卷引用:甘肃省酒泉市2023届高三第三次诊断理科数学试题
4 . 如图所示的五边形
中
是矩形,
,
,沿
折叠成四棱锥
,点
是
的中点,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/25/10e61739-f460-4d4e-9a27-045a0bd7dcef.png?resizew=277)
(1)在四棱锥
中,可以满足条件①
;②
;③
,请从中任选两个作为补充条件,证明:侧面
底面
;(注:若选择不同的组合分别解答,则按第一个解答计分.)
(2)在(1)的条件下求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6718857e3473b4dbe7c14b2a24612ca6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/151f7aef7d0f56e18562f5a4030cf815.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4cab41e3c3e1b04f0cff21aca315238.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6735fcb2c31905447b45697c55a1a16.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/25/10e61739-f460-4d4e-9a27-045a0bd7dcef.png?resizew=277)
(1)在四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8300bca7b13f8487061c5d6d2e82802.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de4f62d0920718d32974ccc06b1bf6b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34f9f450a27660b0996a5f8003c47f5d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b6e6192cf24ada791c26c2d6d434069.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)在(1)的条件下求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d923a338dd2d2e29336b42574d38448.png)
您最近一年使用:0次
名校
解题方法
5 . 已知△ABC的内角A,B,C所对的边分别为a,b,c,且
.
(1)若
,求证:△ABC是等边三角形;
(2)若△ABC为锐角三角形,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e25417ad713e8a494c70da79612b3cc3.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eef1f53a44614a8e672d6093786cd52c.png)
(2)若△ABC为锐角三角形,求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9ecc3aaae2aa289591a3b632f1e0645.png)
您最近一年使用:0次
解题方法
6 . 在
中,角
所对的边分别为
.
(1)证明
;
(2)若
,求
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64e13289528eaf2f29a800c01d4c85ba.png)
(1)证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83577a7a75ed110d15d9b61f27810d4c.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/016a1917bb7afbdc6929614ebd4b297d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
您最近一年使用:0次
7 . 在
中,内角A,B,C所对的边分别为a,b,c,已知
.
(1)求角C的大小;
(2)若
,P为
内一点,
,
,则从下面①②③中选取两个作为条件,证明另外一个成立:①
;②
;③
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01e1dcf28ab3fb22a4aecd0d5d6b5f9e.png)
(1)求角C的大小;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f22fec5a381ae8aca93d876e54c79de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b80ee363635d73f601654339028daec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6eea78bf026d76f1cb9cc3dc9349a193.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b88e9a4616bf02cc44fefd7eaf1e4f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b58bbc02479917ad761a24eaae0dbfd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56bb7fcd7623bc7d2b8d33be10193159.png)
您最近一年使用:0次
2022-05-15更新
|
226次组卷
|
2卷引用:甘肃省酒泉市2022届高考5月联考数学(理科)试题
8 . 在
中,内角
、
、
所对的边分别为
、
、
,已知
.
(1)求角
的大小;
(2)若
,
为
内一点,
,
,则从下面①②③中选取两个作为条件,证明另外一个成立:①
;②
;③
.
![](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/3476f74d5f8748fcce08201b0db1c867.png)
(1)求角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f22fec5a381ae8aca93d876e54c79de.png)
![](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/0b80ee363635d73f601654339028daec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6eea78bf026d76f1cb9cc3dc9349a193.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b88e9a4616bf02cc44fefd7eaf1e4f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b58bbc02479917ad761a24eaae0dbfd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56bb7fcd7623bc7d2b8d33be10193159.png)
您最近一年使用:0次
名校
解题方法
9 . 在
中,角
,
,
所对的边分别为
,
,
,且
.
(1)判断
的性状,并加以证明;
(2)
,
,点
,
分别在线段
,
上,且
,求
的最小值.
![](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/174526cf4c59a3907476ac75b61e08ff.png)
(1)判断
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03837b3769eda7f0d3804cc5ad4a6d60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e899c486dc49e560fc4aca05e16835b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1bd1adfe4cc6566218f19970c2fd3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/977531ee9d2fa2227e31096435b62372.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
您最近一年使用:0次
2022-05-08更新
|
600次组卷
|
2卷引用:甘肃省武威第一中学2022届高三文科数学冲刺试题
名校
10 . 如图,在
中,
,
,
,
是
内部一点,且
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/16/01d5f55d-13fe-434a-894c-dc816ba01225.png?resizew=200)
(1)求
的长;
(2)求证:
为等腰三角形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06201e4f55b78d8b30afb257d5a1b16b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4474a2abc0e638b50e82de1c76ad02c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f81e24376a13d648c2ed0dc73bc710e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db07adbfb878e969f574d220e787d6ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bef81738c7d3a73a396e6344ade130db.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/16/01d5f55d-13fe-434a-894c-dc816ba01225.png?resizew=200)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90e0f35eda1a729fed485f83da5ea9d.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2b83beedb3438153e6f728545fe3e03.png)
您最近一年使用:0次