如图,在三棱柱
中,
平面ABC.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/90a683e2-7f61-43c2-88ac-613640b473fd.png?resizew=118)
(1)证明:平面
平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccb7d2894745ccb63541018f09f9236b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/90a683e2-7f61-43c2-88ac-613640b473fd.png?resizew=118)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df00cdf77ed39ca5a0b305861a693142.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13e98d9de709c421cc482b2ea2c0e5b0.png)
更新时间:2020-01-04 15:49:33
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相似题推荐
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图1,在直角梯形
中,
为线段
的中点.将
沿
折起,使平面
平面
,得到几何体
,如图2所示.
(1)求证:平面
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8d10d5e1189311b4914b3ddf151f51e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbced129627233661d88e9663a9e13c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06123e81c41198c76a3335757fac2c93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4357d5744046d4d44abb09e1ee35fcb.png)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed0ad6e27ea2d5d028f0f76043ccb1f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4eb7e9ad5486cf1c5e506b20c5469e8.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30e536ceabd66ab4850e9207bf8e6e4c.png)
![](https://img.xkw.com/dksih/QBM/2018/8/1/2001325535297536/2002508228886528/STEM/412d05d5b2894752a97e4128502aa185.png?resizew=474)
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解题方法
【推荐2】如图,四棱锥
,
,
,
,
为等边三角形,平面
平面ABCD,Q为PB中点.
![](https://img.xkw.com/dksih/QBM/2022/1/26/2902665447546880/2916946144174080/STEM/036840c5-3b4b-4989-9b05-ee4baa844353.png?resizew=182)
(1)求证:平面
平面PBC;
(2)求平面PBC与平面PAD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/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3bbe4cdd2c154bd9a8073b0d4cecb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec2d5ab801f2a84b78139b0ea2c5032b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://img.xkw.com/dksih/QBM/2022/1/26/2902665447546880/2916946144174080/STEM/036840c5-3b4b-4989-9b05-ee4baa844353.png?resizew=182)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4a0d90148b758fffc6105bc59882f0c.png)
(2)求平面PBC与平面PAD所成二面角的正弦值.
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐1】如图,在四棱锥
中,
,
底面
,
是边长为2的菱形,
,正
所在平面与底面
垂直.
![](https://img.xkw.com/dksih/QBM/2022/4/8/2953847934976000/2954472989581312/STEM/c253a32d-6fb2-4092-b310-2028a71673b6.png?resizew=191)
(1)求证:
平面
;
(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/9641d01140939c44450bf39773272af6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5f1897a7e856b42f8cee0f286ad913d.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/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d41984f53bb280ba8b5ac00a52ce2825.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/2022/4/8/2953847934976000/2954472989581312/STEM/c253a32d-6fb2-4092-b310-2028a71673b6.png?resizew=191)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72221ee5b504d596ff799c0b356aa0ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e866091156cbd7beea724fbbdb25082.png)
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解答题-问答题
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适中
(0.65)
名校
【推荐2】如图,在三棱柱
中,D为AC的中点,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/14/b5a62239-e5a0-41fa-b7c5-3dda04778f73.png?resizew=193)
(1)证明:
;
(2)若
,直线
与平面
所成的角的正弦值为
,二面角
的大小为60°,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f121eabff3c62c1a196d9ca5f6f83f0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d34755c55d43c21b0f05897ef81c1b1f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/14/b5a62239-e5a0-41fa-b7c5-3dda04778f73.png?resizew=193)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a27bad0636a087e38bb1d253d66a231d.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/623f49f1a30f13a3f6706142ed0f92f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b470c4e195cf7a07b7a331ce4b436e03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4e108d5c61e85e0741ec2c484fc5768.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45cbb74984939d59964559c3560ef7ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7de0f1e677c4a1fd058cd6d13dc2dc90.png)
您最近一年使用:0次
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【推荐3】如图,在四棱锥
中,
平面
为矩形,
分别是
的中点.
(1)证明:
//平面
.
(2)若
,求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5f1897a7e856b42f8cee0f286ad913d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/654c6391665a5aee872901309abd4b10.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50f76fcb62af1a4745679c696ec6fbcb.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/21/89ff8954-e40d-42f9-a56d-fb68a516977e.png?resizew=131)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e3be07cb30cbbd7d18e6c4ed1147362.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1885efcff0b903e314057dd153578600.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
您最近一年使用:0次