名校
1 . 如图,在三棱锥P-ABC中,
底面ABC,
.点D,E,N分别为棱PA,PC,BC的中点,M是线段AD的中点,
,
.
![](https://img.xkw.com/dksih/QBM/2020/2/12/2403188036575232/2404736134250496/STEM/2a76a45f-02e9-4493-abef-660bcf222e4b.png)
(1)求证:
平面BDE;
(2)求二面角C-EM-N的正弦值.
(3)已知点H在棱PA上,且直线NH与直线BE所成角的余弦值为
,求线段AH的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/178a27068cf5517ad64f211af10256ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/487b14c446e989c68d0e148cc557dbf2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://img.xkw.com/dksih/QBM/2020/2/12/2403188036575232/2404736134250496/STEM/2a76a45f-02e9-4493-abef-660bcf222e4b.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02438f0423acd0ff2dfa5ffb6abf143f.png)
(2)求二面角C-EM-N的正弦值.
(3)已知点H在棱PA上,且直线NH与直线BE所成角的余弦值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41feec4b238aaf82735726826b7c8dd3.png)
您最近一年使用:0次
2020-02-22更新
|
557次组卷
|
3卷引用:2020届天津市耀华中学高三年级上学期第二次月考试题
解题方法
2 . 如图,在三棱锥
中,平面
平面
,
为等边三角形,
,且
,O,M分别为
,
的中点.
![](https://img.xkw.com/dksih/QBM/2016/2/23/1572493459259392/1572493465501696/STEM/e112da64-89cf-47ca-8c60-0f038e0e7958.png?resizew=273)
(Ⅰ)求证:
平面
;
(Ⅱ)设
是线段
上一点,满足平面
平面
,试说明点的位置
;
(Ⅲ)求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6a94d59dee2d5a8f0425b64b2083825.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8704811c9c5dba854310ae0de2ba6b05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9f63075fdeeb9e765dd696c4ff43ba1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19bc7774144c164f7ebaeca54fa657e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd4fce8e923062b9779553d6f282895b.png)
![](https://img.xkw.com/dksih/QBM/2016/2/23/1572493459259392/1572493465501696/STEM/e112da64-89cf-47ca-8c60-0f038e0e7958.png?resizew=273)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70a56d04dee1d94bb694c34706ee0af4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08452588675f76da2f8d31387b3a8224.png)
(Ⅱ)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffe4f0e847eee390f76f04bb4cf53b31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af57d63e83ef0e183add10cd6beec65b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
(Ⅲ)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6a94d59dee2d5a8f0425b64b2083825.png)
您最近一年使用:0次
2016-12-04更新
|
859次组卷
|
2卷引用:2015-2016学年天津市一中高二上学期期中理科数学试卷
2014·天津河东·一模
3 . 如图,已知正方体
的棱长为2,E、F分别是
、
的中点,过
、E、F作平面
交
于G.
(l)求证:EG∥
;
(2)求二面角
的余弦值;
(3)求正方体被平面
所截得的几何体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8456cee87c4e22351affc28f3a73a0f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6795cae2df43a722e1355e9562d93c09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6825593e8ec77e085f4ee6f581303b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
(l)求证:EG∥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/408871c2b71ef88d6f556ce53cf73cc9.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e663d07f858d7511856d409bfe3cad19.png)
(3)求正方体被平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6825593e8ec77e085f4ee6f581303b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/333a42efbd992938047d2997583cd0fb.png)
![](https://img.xkw.com/dksih/QBM/2014/5/15/1571722324058112/1571722329202688/STEM/be3f1886b9b643b9acce1e499af3f7ab.png)
您最近一年使用:0次
12-13高一上·北京·期末
解题方法
4 . 在四棱锥
中,底面
是直角梯形,
,
,
,平面
平面
.
(1)求证:
平面
;
(2)求平面
和平面
所成二面角(小于
)的大小;
(3)在棱
上是否存在点
使得
平面
?若存在,求
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45acdbac251ca6b76a166c1242e71df9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c0073c8e806d0399a6983e163f0fd176.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78a3fd5284e160896f07ce367645fd04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1b489c25405ce48699d4f0a62820bed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06ba22238cdff318a4bd9d4d746b3229.png)
(3)在棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5865d488a9cf1181016fd2e866177cdd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b505e0df1131e3a93fc81d13f6e224e7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/16/fa4fd412-897c-4621-b148-dc248d6cc7a6.png?resizew=135)
您最近一年使用:0次
2016-12-02更新
|
651次组卷
|
5卷引用:2013届天津市天津一中高三第三次月考理科数学试卷
(已下线)2013届天津市天津一中高三第三次月考理科数学试卷(已下线)2011-2012学年北京市育园中学高一第一学期期末考试数学(已下线)2011-2012学年北京市海淀区高三上学期期末考试理科数学北京西城回民中学2018届高三上期中数学(理)试题北京市东城区2018届高三上学期期中考试数学试题