已知,如图四棱锥(1)中,
,
为平行四边形,
,
平面
,
,
分别是
,
中点,点
在棱
上.
![](https://img.xkw.com/dksih/QBM/2021/2/2/2649268308844544/2652804818427904/STEM/856932b2-3ca0-41d0-aeff-0bf06afe2c59.png)
(1)证明:平面
平面
;
(2)若二面角
的余弦值为
,求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36b72c6d2ae4924f930c437542b3356a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff5a86745bfe1dfe7bc2683811210330.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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://img.xkw.com/dksih/QBM/2021/2/2/2649268308844544/2652804818427904/STEM/856932b2-3ca0-41d0-aeff-0bf06afe2c59.png)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6501f1c913a4ef64957a2f01ab5baa15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/590fd474cea16e23415f0e277f8f51f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ae6d1d40c8300298aa50b94439ed5d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03428a8f91a5674cb8f54766c165f7e.png)
2021·江西吉安·模拟预测 查看更多[4]
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更新时间:2021-02-07 10:08:07
|
相似题推荐
【推荐1】如图,在三棱锥
中,△
是边长为
的正三角形,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/7/27fbec8e-05ed-4c41-9ec5-cda0bfbca20f.png?resizew=159)
(1)求证:平面
平面BCD;
(2)若点E在棱BC上,且
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的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
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(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf6dc837ae85207789b94d109c5c2eb.png)
(2)若点E在棱BC上,且
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bffd657e48b15b9b54a55817e2c26b22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52753d89bf58589e2e83b19bd3d140b8.png)
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【推荐2】如图,四棱台
中,底面ABCD是菱形,点M,N分别为棱BC,CD的中点,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/2023/2/22/3180344722972672/3181217779449856/STEM/066e6a6e50084d078015b46759734aa6.png?resizew=212)
(1)证明:平面
平面ABCD;
(2)当
时,求多面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9a0c3a4e61b97fa9bc58f3179fc2958.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67fb18590fddcdcd504207d064ee8539.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://img.xkw.com/dksih/QBM/2023/2/22/3180344722972672/3181217779449856/STEM/066e6a6e50084d078015b46759734aa6.png?resizew=212)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a5628323a7eeb11213df5c9048b3543.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/056c2272e0d10d6dd9706e6324d8e62d.png)
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您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐1】如图所示的五边形
中
是矩形,
,
,沿
折叠成四棱锥
,点
是
的中点,
.
中,可以满足条件①
;②
;③
,请从中任选两个作为补充条件,证明:侧面
底面
;(注:若选择不同的组合分别解答,则按第一个解答计分.)
(2)在(1)的条件下求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6718857e3473b4dbe7c14b2a24612ca6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/151f7aef7d0f56e18562f5a4030cf815.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4cab41e3c3e1b04f0cff21aca315238.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6735fcb2c31905447b45697c55a1a16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8300bca7b13f8487061c5d6d2e82802.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de4f62d0920718d32974ccc06b1bf6b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34f9f450a27660b0996a5f8003c47f5d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b6e6192cf24ada791c26c2d6d434069.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)在(1)的条件下求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c2bc5e50b8dfa02601c70822252854a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d923a338dd2d2e29336b42574d38448.png)
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解答题-证明题
|
适中
(0.65)
名校
【推荐2】如图,已知三棱柱
中,侧面
底面
为等腰直角三角形,
.
![](https://img.xkw.com/dksih/QBM/2022/2/13/2915478992084992/2918496875298816/STEM/df3ea88191e440118041f55865aa92c6.png?resizew=182)
(1)若O为
的中点,求证:
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce04b35c265cc9c48b60204bd2f718ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da7100609b771b73f1e169d5462b73fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/209acf15985d1ea1ad86fc4a37e38c0b.png)
![](https://img.xkw.com/dksih/QBM/2022/2/13/2915478992084992/2918496875298816/STEM/df3ea88191e440118041f55865aa92c6.png?resizew=182)
(1)若O为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/000da9bafa0bddcfdd1085c528d59c70.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
您最近一年使用:0次