如图,在四棱柱
中,底面
是等腰梯形,
,
,
,顶点
在底面
内的射影恰为点
.
![](https://img.xkw.com/dksih/QBM/2021/6/2/2734197082308608/2782390608560128/STEM/680e47a96a4940d4a9b0d9af9da6d70f.png?resizew=280)
(Ⅰ)求证:
平面
;
(Ⅱ)若直线
与底面
所成的角为
,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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d2c15801fee2405573677484f5dcfa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08ad8d16722f5b9e7fd2602f14d5ffbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6795cae2df43a722e1355e9562d93c09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://img.xkw.com/dksih/QBM/2021/6/2/2734197082308608/2782390608560128/STEM/680e47a96a4940d4a9b0d9af9da6d70f.png?resizew=280)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da7977ab975efa6411cc17de39be70d9.png)
(Ⅱ)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15615de1a6df206dbd081251f676578e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/679748eab882a6be0fefd2cc300349a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
更新时间:2021-08-09 12:11:05
|
相似题推荐
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】已知平行六面体
的各棱长均为2,
,M,E分别是线段
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/22/7c1e61c2-8434-46d9-8c3f-8f847fcecc4c.png?resizew=179)
(1)证明:
平面
;
(2)求平面DME与平面
的夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa55c6ef551cb92a87525e90b20b0575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61ea285e96bf2e3b6406151bb694f10a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/22/7c1e61c2-8434-46d9-8c3f-8f847fcecc4c.png?resizew=179)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac61c24f99a4e466f1e2ea011893866.png)
(2)求平面DME与平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac61c24f99a4e466f1e2ea011893866.png)
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解答题-证明题
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名校
【推荐2】如图,在三棱柱
中,直线
平面
,平面
平面
.
;
(2)若
,在棱
上是否存在一点
,使二面角
的余弦值为
?若存在,求
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06ad7c180d6d084ecb25f23cb6fe9b10.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0671b4776e142e17a79af5b3f0378ef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1de5964353beb55c5058b2a431eecaf.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9008767d531e72e94dee8452aedca97a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c23129f02a89e68ca40c08b32563475.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a69d166677557cadb3da32b4a7e152e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55abe7008585043c035ade44c9b54398.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,四棱锥
中,
平面
,四边形
是梯形,
,
,
,
,点E是
的中点,F是
上的点,满足
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/13/89dd10af-254f-4f5c-b49c-9d6c13d7453e.png?resizew=173)
(1)求证:点F在平面
内;
(2)求平面
与平面
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45fbffb9e2c7fa7c5006cde8da0cabe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5acb763021bf166ca719d07223591d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6037bba27008abc96a6dba99753549ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd15b6452d74015b8ce15ba3a9b13866.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7aeb2a8d1437eeb4482c3b6ad9f315.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d04c61a6fadebc90325f5eac65128d7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/13/89dd10af-254f-4f5c-b49c-9d6c13d7453e.png?resizew=173)
(1)求证:点F在平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2977ae4bfa32de8c6f0fb136205c4fe7.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2977ae4bfa32de8c6f0fb136205c4fe7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
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解答题-问答题
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适中
(0.65)
名校
解题方法
【推荐2】如图,在四棱锥
中,
平面
,
,
,
,点
是
与
的交点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/1/bfd0f88f-a674-4a1d-afa5-5fe255a1871d.png?resizew=131)
(1)求二面角
的余弦值;
(2)若点
在线段
上且
平面
,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/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/633bf2de732ae51fc06ef3d559915da0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7dbf31dfd36aa456a63bafea8bc1985.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4bcc4cc03daa9957f78c7f40443f15e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/1/bfd0f88f-a674-4a1d-afa5-5fe255a1871d.png?resizew=131)
(1)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a438393ddfc7da1804baf4932442bb35.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7592c4f01c8e06c7ee90df5b9413a9f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/218054144a13435580cd132b9459546c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
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解答题-证明题
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(0.65)
名校
【推荐3】如图,在四棱锥S﹣ABCD中,底面ABCD是直角梯形,AB垂直于AD和BC,侧棱
,E为SB的中点,且
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/cd2858bc-4a47-4087-8d9a-0cf526e90627.png?resizew=169)
(1)求证:
平面
;
(2)求面SCD与面SAB所成二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b07fa01f6fbe9c6474ef47db33dfb8b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ca27f9fa673fa014bb34f92355d6714.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ffbcd82b98a9ae69aa4ee28bb49a907.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/cd2858bc-4a47-4087-8d9a-0cf526e90627.png?resizew=169)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f4c3f9dd5d0343597a7f58a1989b537.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21665d21bbfb04410c78345de1fd15ae.png)
(2)求面SCD与面SAB所成二面角的余弦值.
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