如图,在四棱锥
中,底面
是正方形,
底面
,
,点E是
的中点,点F在边
上移动.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/25/3d054ac0-a371-46bd-9efb-82f024275fef.png?resizew=176)
(Ⅰ)若F为
中点,求证:
平面
;
(Ⅱ)求证:
;
(Ⅲ)若二面角
的余弦值等于
,求
的值.
![](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/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f83a04565a8ebaa111894b724b0ba266.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/25/3d054ac0-a371-46bd-9efb-82f024275fef.png?resizew=176)
(Ⅰ)若F为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06222ee533c2484ab25321a6abbf98cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(Ⅱ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2c95b6b6e8fd9fc8e8084b5706b4b48.png)
(Ⅲ)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5f8dfb22b415219ba7af3dc7e3d808.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/743c08870d66a766fa25298adf4dbf89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72acf5ee54c89dede4358c61ecd7a101.png)
更新时间:2020-04-08 22:30:21
|
相似题推荐
解答题-证明题
|
适中
(0.65)
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解题方法
【推荐1】如图,在多面体ABCDE中,
平面BCD,平面
平面BCD,其中
是边长为2的正三角形,
是以
为直角的等腰三角形,
.
(1)证明:
平面BCD.
(2)求平面ACE与平面BDE的夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa7fb4bb4caccf79639a126064771da5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2b265d121f9ebc13671a5719604476a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/661ff55b5ebbadfb600989af3cfce2fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a72dfbf0138a611174c36ce077e0c47.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68b40d0d2f3cdd8981bb792ad87efb42.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/28/80104c86-9407-4b24-890b-ff4d4ed6c129.png?resizew=157)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6ae72f5e5891249caa10c43224da89c.png)
(2)求平面ACE与平面BDE的夹角的余弦值.
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【推荐2】如图,直四棱柱ABCDA1B1C1D1的底面是菱形,AA1=4,AB=2,∠BAD=60°,E,M,N分别是BC,BB1,A1D的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/13/93571516-2dd0-4f51-b374-e8207b84a521.png?resizew=152)
(1)证明:MN∥平面C1DE;
(2)求三棱锥NCDE的体积.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/13/93571516-2dd0-4f51-b374-e8207b84a521.png?resizew=152)
(1)证明:MN∥平面C1DE;
(2)求三棱锥NCDE的体积.
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【推荐1】在四棱锥
中,底面ABCD是菱形,
,
平面ABCD,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/19/0b8ff67d-f743-4128-acf5-3928c2b0d02f.png?resizew=164)
(1)求证:
;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f83a04565a8ebaa111894b724b0ba266.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/19/0b8ff67d-f743-4128-acf5-3928c2b0d02f.png?resizew=164)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e4125524caac016727c80d2722c5ba3.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1636b4530c0b42d0e0b649e90e3b9e85.png)
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【推荐2】如图所示,在四棱锥
中,
平面
,
是线段
的中垂线,
与
交于点
,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/2020/7/7/2500980319559680/2501550599749632/STEM/4500e48a644c4309b9bbf53239d3360d.png?resizew=236)
(1)证明:平面
平面
;
(2)求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4494a85de0be0b97a69348115aef8513.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41cd5c4f8b106d01e0e431078e1a468b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78691dacfa00dd2448b1ba94b264ec8b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b42602dabcdc7bdaba0ee0af37d71f0.png)
![](https://img.xkw.com/dksih/QBM/2020/7/7/2500980319559680/2501550599749632/STEM/4500e48a644c4309b9bbf53239d3360d.png?resizew=236)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f04c222223dae9ef27d4c132534d9848.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
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【推荐1】如图所示,已知直棱柱
的底面四边形是菱形,点
,
,
,
分别在棱
,
,
,
上运动,且满足:
,
.
![](https://img.xkw.com/dksih/QBM/2021/3/15/2678615089283072/2682818580021248/STEM/efd911b2fe424659a35c3162731608c0.png?resizew=215)
(1)求证:
平面
;
(2)是否存在点
使得二面角
的正弦值为
?若存在,求出
的长度;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.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/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/626db48efbecf4e318252ba13baff47d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efff82bbfb9e24b2b412a52dc0465056.png)
![](https://img.xkw.com/dksih/QBM/2021/3/15/2678615089283072/2682818580021248/STEM/efd911b2fe424659a35c3162731608c0.png?resizew=215)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06222ee533c2484ab25321a6abbf98cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c51c4a1148587943fe9ba210f6141ee.png)
(2)是否存在点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e807172fa9eca2416f92f341adc06165.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e64e76a4c1e5934f51cdca2ffbc8313f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63a253c7fdf589ee3dece13d5b5b5732.png)
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解答题-问答题
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解题方法
【推荐2】在直三棱柱ABC-A1B1C1中,AB⊥AC,AB=2,AC=AA1=2,设
(λ>0).
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/27/d9866251-6760-4865-bad1-7bf23b900b16.png?resizew=141)
(1)若λ=1,求直线
与平面A1C1D所成角的正弦值;
(2)若二面角
的大小为60°,求实数
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c9acc8e0a6a969fa8227b84a088338.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/27/d9866251-6760-4865-bad1-7bf23b900b16.png?resizew=141)
(1)若λ=1,求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69a7bcc1efb8a2ff57d64b6d057da463.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/576ce8ec4a5330edbc3af84bde5e760f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
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【推荐3】如图,四棱锥
的底面
是长方形,侧棱
底面
,
,E是
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/9592e0ed-e67d-441f-b47b-16781ed64db1.png?resizew=199)
(1)证明:
平面
;
(2)若点F在线段
(不包含端点)上,二面角
为
,且直线
平面
,求线段
的长.
![](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/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c2318ff49463f17ddd0afff48ed4988.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/9592e0ed-e67d-441f-b47b-16781ed64db1.png?resizew=199)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/373f735f0f04d11f1951eaef1bb78b6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
(2)若点F在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad6a0cee8226e82cc57916e10d533369.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0da6b7bf79e79c720d2326b4ea14a185.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45fbffb9e2c7fa7c5006cde8da0cabe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d004d2d115b477ade6af7ddb93db0df8.png)
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