如图,在五面体ABCDE中,已知
平面BCD,
,且
,
.
![](https://img.xkw.com/dksih/QBM/2022/4/19/2961648035373056/2962936898158592/STEM/7cb309fadef94890bb12bde8ba3c1bf2.png?resizew=179)
(1)证明:平面
平面ABC;
(2)设平面ABE和平面CBE的夹角为
,平面ABE和平面DBE的夹角为
,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4025b7c8380b8aeb5a31a5e14eafa98b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d05426a41ec7b22c0445bfe78d786c8d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7422660f0635be92e11838af5f4b4b5e.png)
![](https://img.xkw.com/dksih/QBM/2022/4/19/2961648035373056/2962936898158592/STEM/7cb309fadef94890bb12bde8ba3c1bf2.png?resizew=179)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed5f0cfc1049f84a04c81bd213afb8d9.png)
(2)设平面ABE和平面CBE的夹角为
![](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/ffa3205b1df826d63914dcb55bb3ab43.png)
更新时间:2022-04-21 14:13:27
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相似题推荐
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图,在四棱锥
中,
,
,
,E为棱
的中点,
平面
.
平面
;
(2)若二面角
的大小为
,求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34e0a957a55460c72673c0f2ee90dbb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a0e5697eca3f5205cb7b343648240bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/639bec6242a4b3f7bfb4b7033a67328c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1636b4530c0b42d0e0b649e90e3b9e85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30c20e88a33043f4279fff360c81006e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
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解答题-证明题
|
适中
(0.65)
解题方法
【推荐2】如图,已知侧棱垂直于底面的四棱柱
中,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/13/7e1fe7ea-9f36-46dd-9fac-92de6060f7db.png?resizew=141)
(1)若
是线段
上的点且满足
,求证:平面
平面
;
(2)求二面角
的平面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d262480ffb55b7617f44b63f130c154a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ea82794c0cf262948c38aa776f4b059.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87b2f446cccf2652c090e99a75beb3bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/295640e886a3a29c5159a93fa287ee68.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/13/7e1fe7ea-9f36-46dd-9fac-92de6060f7db.png?resizew=141)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a696a182fff038a86b2bbe8ca099442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8585f248084f3ed36109299301e4f129.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e54cf75bbfc9db93d27937c8b8e977b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73845d4d663b3de0b281611fe2c762fe.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b349fce5141b5b10ae82da7a49f0e9c7.png)
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解答题-问答题
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适中
(0.65)
【推荐1】如图,在三棱锥
中,
是正三角形,
,
是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/279d18e1-d2c2-4886-841a-3acfe9f70b88.png?resizew=176)
(1)证明:
;
(2)若
,
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c025ee3317be1099b7bf03a11e37ed4.png)
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![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/279d18e1-d2c2-4886-841a-3acfe9f70b88.png?resizew=176)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f90197a948331e61db644266368017e3.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/209acf15985d1ea1ad86fc4a37e38c0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb8c91e4c85a9da7f54b2237d870a50d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1047ac90668f2e8eafbc26afe983b756.png)
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解答题-问答题
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适中
(0.65)
解题方法
【推荐2】如图所示正四棱锥
,
,
,
为侧棱
上的点,且
.求:
的表面积;
(2)若
为
的中点,求平面
与平面
所成的二面角的余弦值;
(3)侧棱
上是否存在一点
,使得
平面
.若存在,求
的值;若不存在,试说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04c56f3d2a9c05c3a13330af7a261889.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b2883beed42e46f8f379b02ea3b68b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a6e2867f32d3f1c3cd36cd3a11a8580.png)
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(3)侧棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c2bc5e50b8dfa02601c70822252854a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fea0808c7df5a3fa6678ee5406b35b25.png)
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