如图1,在平面四边形
中,
,
,
,
,将
沿
翻折到
的位置,使得平面
平面
,如图2所示.
(1)求证:
平面
;
(2)设线段
的中点为
,求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6992cf6aa556bf6e61f098ee75f2de66.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3185a8075eea774ea1c6298fd1d0f5af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a2fc51de957401a6193689497e6014d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1cfc9df9c661bd93b3f4f51f91534c4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ffbcd82b98a9ae69aa4ee28bb49a907.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dea2ae9d515f9ab351ad72306b776ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72e49817548cb45b3d1e58570644c6fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/448cbac9a1ef3de7538a6b30cdc39582.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/20/4625f1d8-5e44-46d5-9926-44312786aed4.png?resizew=426)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a0787d2cb66d00c49d3348b52acd407.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9c9cfa597b444b5c9dbae7a825a695.png)
(2)设线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c2bc5e50b8dfa02601c70822252854a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df7fdfebdbaddc49e8991ec47d2fb076.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
更新时间:2023-07-16 20:22:16
|
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,在三棱柱
中,所有棱长均为1,
.
平面
.
(2)求三棱柱
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01805084c9e7371b1f869711a2d89b99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ce03b310edce42191f9fa75a1c909ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
(2)求三棱柱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
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【推荐2】如图,已知三棱柱ABC-A′B′C′的侧棱垂直于底面,AB=AC,∠BAC=90°,点M,N分别为
和
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/20/441123f2-0a0e-423b-852d-7124a394ea25.png?resizew=136)
(1)证明:
平面
;
(2)设
,当λ为何值时,
平面
?试证明你的结论.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d65242718f20b2742841c58ee7642cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54c20b6dab50010f7a5eef15fecc72f2.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/20/441123f2-0a0e-423b-852d-7124a394ea25.png?resizew=136)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcf19a7f0dd0cdf59516ae585025110.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47829d206eaf9ffdaf5a49d8234cd34c.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfc3f0885d321b62e9154e8118436e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00c25c4259d935d6e6fabe5c3fc1f43c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e6e1bfcef57250dcc75d503a5241444.png)
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解答题-证明题
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【推荐1】如图,已知四棱锥
中,
,
,
,
,
分别为
,
的中点.
![](https://img.xkw.com/dksih/QBM/2021/1/11/2634045199212544/2635188613898240/STEM/dfe2e990-00c6-4542-ac4f-5c7d6db6a5ef.png?resizew=257)
(1)证明:点
在平面
内;
(2)若平面
平面
,
为等边三角形,且
,求平面
和平面
所成锐二面角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd8e727e4efc22b49649f71ae9c9d84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9060f03b9ee41d70d135b1e1a8902ce9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64f1161e0345b3646c71365430dccbb1.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/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://img.xkw.com/dksih/QBM/2021/1/11/2634045199212544/2635188613898240/STEM/dfe2e990-00c6-4542-ac4f-5c7d6db6a5ef.png?resizew=257)
(1)证明:点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87c0bfeadcf17b2a45896071f07a4a5a.png)
(2)若平面
![](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/55a675310c8ba418e5a59beb7317e21e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2ddd49625097d0a78df7170be4f882e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87c0bfeadcf17b2a45896071f07a4a5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
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【推荐2】 如图,已知
平面
是正三角
形,
.
(Ⅰ)在线段
上是否存在一点
,使
平面
?
(Ⅱ)求证:平面
平面
;
(Ⅲ)求二面角
的正切值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7cbe3ec31a79a171dcf274ff99e50762.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c773f72c053e7287702e3f7e8c236593.png)
形,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f779e7f5f53e4377b9a0a8e945d562.png)
(Ⅰ)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8f70cf3f6c7acbf60d4a4ca0ce89619.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
(Ⅱ)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84181cfc406696b59161b8d4c417099c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
(Ⅲ)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b5a82f851479ec3ae9dc7aca67a97ab.png)
![](https://img.xkw.com/dksih/QBM/2010/4/2/1569689467109376/1569689574719488/STEM/eba6fd8855f449109b673e53ece64459.png)
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解答题-证明题
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【推荐1】如图,在以P,A,B,C,D为顶点的五面体中,平面ABCD为等腰梯形,
,平面PAD⊥平面PAB,
.
(2)若
,求直线PD与平面PBC所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43cd91de06eaf2e4b0939cc7fb17edfe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83640592853a53872d7af69c0cffc1bb.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/854f4df35b7d57bf69dea9f6cafa8fae.png)
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【推荐2】如图,在四棱锥
中,平面
平面ABCD,底面ABCD为菱形,
,E为AD中点.
(1)证明:
;
(2)若
,求直线PE与平面PCD所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7fcc62f1c0536d8f82409e8c8df7beb.png)
![](https://img.xkw.com/dksih/QBM/2021/11/14/2850893510656000/2856294347481088/STEM/db75a656e59840aa97384bed7cee238c.png?resizew=361)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b8a1ea8fca7c80a86dbe4d85cf9707d.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bb5b12692517a39c320f99a479eb055.png)
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