如图,在四棱柱
中,底面ABCD是菱形,AB=2,
,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/22/6bccdd56-07f7-4937-8056-2289194dbae3.png?resizew=189)
(1)求证:平面
平面ABCD;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebecdc0f0f815ff0083d85d3f539b36d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b046a91816b74aab46ff92889ae6eb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5da3a51130be3a7757fc07f709b58c7d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/22/6bccdd56-07f7-4937-8056-2289194dbae3.png?resizew=189)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686e56830bfadfdde4e09d299f3738f9.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b48414158019504a81bdfa3a8836b84b.png)
20-21高三上·河北·阶段练习 查看更多[2]
河北省“五个一名校联盟”(张家口一中、唐山一中、保定一中、邯郸一中、邢台一中)2021届高三上学期第一次诊断考试数学试题(已下线)黄金卷17 【赢在高考·黄金20卷】备战2021年高考数学全真模拟卷(广东专用)
更新时间:2021-01-02 09:46:57
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐1】在直角
中,
,M,N分别为
的中点,
,如图1.将
沿
折起至
的位置,如图2.连接
.
![](https://img.xkw.com/dksih/QBM/2022/5/20/2983390734049280/2984074456236032/STEM/c3079ffc-f12b-4211-a281-a9335e3e1a7a.png?resizew=315)
(1)证明:平面
平面
;
(2)连接
,若
,求平面
和平面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5881068127a39caf319492b4177204f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5181b97a7e43959b8455680157c3b644.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98013a5042685a1db94249e70c62c09a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/999c42a021bdc576f097246b9e64d986.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0eb0c11e4b7aa9030a6691aee35eed0.png)
![](https://img.xkw.com/dksih/QBM/2022/5/20/2983390734049280/2984074456236032/STEM/c3079ffc-f12b-4211-a281-a9335e3e1a7a.png?resizew=315)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c309e58bf083bad13abd549720a63a22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc775691cd03e1abed66100c942eb3a8.png)
(2)连接
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dafebaaf13781120dc57c277d0267c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb114762ae8d193ab1e82045ca1a5fa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89abfe070487c1296d855093aa9596e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da8bf0fb06e0382ab2d43366f42ae8a0.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐2】如图,在四棱锥
中,底面
是边长为
的正方形,
,
分别为
,
的中点,侧面
底面
,且
.
![](https://img.xkw.com/dksih/QBM/2022/8/11/3042192923885568/3042991067815936/STEM/6f0956cf9518406995836e110309c915.png?resizew=204)
(1)求证:
平面
;
(2)求证:平面
平面
;
(3)求三棱锥
的体积.
![](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/0a6936d370d6a238a608ca56f87198de.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/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1b7201f9eb7e7c10042c096e0c9f15c.png)
![](https://img.xkw.com/dksih/QBM/2022/8/11/3042192923885568/3042991067815936/STEM/6f0956cf9518406995836e110309c915.png?resizew=204)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06222ee533c2484ab25321a6abbf98cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
(3)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c10c16d2d9d22c4b34ddd965e26aa0d7.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】已知平面
,
,求二面角
的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c04e920761449b3f5ca5ac53c8abfc4e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72bd8c430f0620d49b3668a03d92e5ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/754bbd99327195520a4ca3ce3b9a0577.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐2】如图所示,在四棱锥
中,底面
是边长为2的正方形,其它四个侧面都是侧棱长为
的等腰三角形.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/14/9ddb9af6-7663-480c-987e-8bbb9348e43a.png?resizew=202)
(1)求二面角
的大小;
(2)在线段
上是否存在一点
,使平面
平面
?若存在,请指出点
的位置并证明,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/2967337e3fcb228dded64ab0c41a17e0.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/14/9ddb9af6-7663-480c-987e-8bbb9348e43a.png?resizew=202)
(1)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47d294d69caac577339f11f477b2047e.png)
(2)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22583ac400216f5aa56a84284efe4b12.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐3】已知三棱锥
的底面
为等腰直角三角形,
,
,平面
平面
,三角形
不是钝角三角形且面积为
,点
在面
上的射影为点
.
(1)证明:
平面
的充要条件是
;
(2)求二面角
的正弦值的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a69550d878381f6e8fb436e88638f070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/714cc3707bba3bfdb56e251999be8592.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf6dc837ae85207789b94d109c5c2eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7abd284f76d9f5769bc189508ce2572b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/3/f8a2a064-a3d1-4d6b-961a-db7a9bfd0b19.png?resizew=170)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7ea3d743f8f55357958e5a6e0bc2a14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e735a28578ba191da6d4f3b0f8e8729.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c2898853a3396f0878af9eac934416d.png)
您最近一年使用:0次