如图,在四棱锥
中,四边形
为菱形,
,
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/2022/5/3/2971600724992000/2975063248052224/STEM/262cecd6-0f66-4f46-867a-3f92d241e1cf.png?resizew=253)
(1)证明:
平面
;
(2)若
,
,
,求平面
和平面
所成二面角的正弦值.
![](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/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32d0710321d97361e5782124bbf7f0c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/2022/5/3/2971600724992000/2975063248052224/STEM/262cecd6-0f66-4f46-867a-3f92d241e1cf.png?resizew=253)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19a665ba024f2840ce5aef3765249341.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f37269a62f97efcf4961ef2ca33c6def.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1682d306c38087d9e6f7efb9cec596a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
更新时间:2022-05-08 17:24:35
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
【推荐1】如图所示的几何体中,
为直三棱柱,四边形
为平行四边形,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/2d42ff77-b6ba-41aa-9087-11bf91629da3.png?resizew=171)
(1)若
,证明:
四点共面,且
;
(2)若
,二面角
的余弦值为
,求直线
与平面
所成角.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f3ba8b214034c287276f4966069d95e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd9cba0ec6619ed299ee9ab9cdfe482b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/22/2d42ff77-b6ba-41aa-9087-11bf91629da3.png?resizew=171)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46fe926770d2354e172dec02f5ce2efe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca6ecdde08c6bd0cfd5db1ed78e8bf5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad2a68040bca2f03bd60301321b06973.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18605b48a61e6a61f34e0d251add2228.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9ea6229a7f27d2946229a1769aa9235.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/821309f088a175c00dc0f4828334503d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/019efc97696ff32a8c1bcb82c48d2485.png)
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【推荐2】如图,
平面
.
![](https://img.xkw.com/dksih/QBM/2020/5/8/2458527791980544/2459071109775360/STEM/3f5f3a1476fe48a9a8ec823d72d9c344.png?resizew=119)
(1)证明:
//平面
.
(2)若几何体
的体积为10,求三棱锥
的侧面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed04b01505bbd8a4ac0bc12e46f23bf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/853dc22648690b7f88295b9b9dd1f580.png)
![](https://img.xkw.com/dksih/QBM/2020/5/8/2458527791980544/2459071109775360/STEM/3f5f3a1476fe48a9a8ec823d72d9c344.png?resizew=119)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3182db896bc2462331796e2a6108363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c66d99a6a8415ddad22bbed33b64cfb.png)
(2)若几何体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6222968fb42829e03773017457472ff1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51f73a0ca4e6c794242489066fddb6c5.png)
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【推荐3】如图所示,已知三棱锥
,D为
的中点,且
是正三角形,
.
![](https://img.xkw.com/dksih/QBM/2021/4/28/2709763705954304/2808664621621248/STEM/b330176d-c1fd-43e9-8ed9-5453558a3d4c.png?resizew=276)
(1)求证:
平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e2ea5a2c4ec45f70ec28a1453a10411.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0bb4ef08f6070a6bbc54ea9c4f130d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/036de574712cad14bddadf6653c7e714.png)
![](https://img.xkw.com/dksih/QBM/2021/4/28/2709763705954304/2808664621621248/STEM/b330176d-c1fd-43e9-8ed9-5453558a3d4c.png?resizew=276)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6ea6e7aec788b4a60aeabdb948a95c6.png)
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解题方法
【推荐1】如图,正方体
中,M为
的中点.
![](https://img.xkw.com/dksih/QBM/2021/4/28/2709720454840320/2771981806338048/STEM/dffc9bc5-9d42-4e53-8420-c300aa4db79e.png?resizew=254)
(1)若点N满足
.求证:
平面
;
(2)求平面
与平面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://img.xkw.com/dksih/QBM/2021/4/28/2709720454840320/2771981806338048/STEM/dffc9bc5-9d42-4e53-8420-c300aa4db79e.png?resizew=254)
(1)若点N满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5a36eb94b79db6916c9aa98843efd4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92a365939377980a322f2a232ca47964.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fed2f706801662432b68797e72647c6e.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fed2f706801662432b68797e72647c6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
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解题方法
【推荐2】在三棱柱
中,侧棱
底面
,
分别是
、
、
的中点,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/10/c199368d-abb2-4303-a5df-3b4e141caba5.png?resizew=190)
(Ⅰ)证明:
;
(Ⅱ)求平面
与平面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f57b7e63faf8ca707fa15413a32abce0.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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a7077d7e5ceacb3cd5d7338a8da069c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/002c709e9fee8d477bddfe595cc760f7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/10/c199368d-abb2-4303-a5df-3b4e141caba5.png?resizew=190)
(Ⅰ)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36c4559d27e3905980d1a4f1856f07de.png)
(Ⅱ)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
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【推荐3】如图1,在矩形
中,
为线段
的中点,
为线段
的中点,将
沿直线
向上翻折,使得
,如图2所示.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/23/5a9100cb-4671-4b3c-9862-eae2bcef5915.png?resizew=392)
(1)求证:
平面
;
(2)求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d483d64697d534891f1265441f6c515.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e52a8f07834cbbbe4224962672fbbb2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25c28359f8d8da9eaf4672a6cf8ae4f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c219d82e5a081750b88cfd913f01b667.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/23/5a9100cb-4671-4b3c-9862-eae2bcef5915.png?resizew=392)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7b7675ff57bdccb95a8241c1cd09f05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01ff27eea7545bb06f9472f91290c54e.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ddc76d96d6951ebfef3fe63892a1114.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/678b28fddb166d90878d24d6e5481080.png)
您最近一年使用:0次