如图,已知
平面
,
平面
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/8/341e935e-35d1-4a9c-9235-ced0cb49e87a.png?resizew=233)
(1)设
是直线
上的点,当点
在何位置时,直线
平面
?请说明理由;
(2)若
,求平面
与平面
所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca5dd496ee0c1170ef6dcc48266ee444.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1822559ef3be853ea41052219cd39652.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74b68e685328f5cb570f25e988c10d45.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/8/341e935e-35d1-4a9c-9235-ced0cb49e87a.png?resizew=233)
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eaf9403ecd2ae90269297499ba6c7182.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fffa3d9c32da53b0ea0c338012ea20c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34be4e71cabf458f17a6cd7f24bc70af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
更新时间:2021-05-07 21:12:05
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
【推荐1】如图,在四棱锥
中,
平面
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cf6af658b0b84c133ef7df06edaccc0.png)
,
,
为
中点.
![](https://img.xkw.com/dksih/QBM/2019/6/7/2220498501763072/2220734486274048/STEM/f5396dcc03b24d7aa6e79317a5a17852.png?resizew=122)
(1)求证:平面
平面
;
(2)线段
上是否存在一点
,使
平面
?若存在,求
的值;若不存在,说明理由.
![](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/5cf6af658b0b84c133ef7df06edaccc0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d783fe7f3ce673d5d21281174e7a7968.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da35bb9885f79a36532f21139f9f99d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/2019/6/7/2220498501763072/2220734486274048/STEM/f5396dcc03b24d7aa6e79317a5a17852.png?resizew=122)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78a3fd5284e160896f07ce367645fd04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b37793a3a810e823e10c340986f55ddd.png)
(2)线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/373f735f0f04d11f1951eaef1bb78b6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ae8768996ca9a0f2c5d9a19abbd54df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/243fcd0b5e7fc1a4d55e191f5fcbd332.png)
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解答题-证明题
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名校
解题方法
【推荐2】如图,已知四棱锥
的底面是边长为2的菱形,
,点E是
边的中点,
交于点O,
,且
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/23/eec094cb-e945-4d4e-a75d-dbb1f1bbd738.png?resizew=191)
(1)求证:
;
(2)在线段
上找一点F,使得
平面
,并求此时四面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7222a2d702fe89e8060d0ae30726ea6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa8a7f03ee87eda54e19b79a183d6f45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63864e565fc5d07d748a61b542294484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3e126c16032892966489053f44b9048.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/23/eec094cb-e945-4d4e-a75d-dbb1f1bbd738.png?resizew=191)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c65334978b0519b379910dfc4acf8344.png)
(2)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9d32e76582bf550593fdef53e081225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b37793a3a810e823e10c340986f55ddd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f107bd06ad6af2ff8d5aaa9ace12d9a0.png)
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解答题-问答题
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适中
(0.65)
名校
【推荐1】设矩形
中,
,点
,
分别是
,
的中点,如图1.现沿
将
折起,使点
至点
的位置,且
,如图2.
(1)证明:
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/84901d928aa92cd39a04981c56002608.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c771a4feb150ad9cff8d70431c97eb17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d1b9d577c1959f2c15b9823d06ba592.png)
![](https://img.xkw.com/dksih/QBM/2020/8/5/2521508738908160/2522583067435008/STEM/dce6826db0cc497284dfca5cb913c6d7.png?resizew=292)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a22d6b860f06fe23618b0d3de6768fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed4cba9d2412e4a28f8740bddd5738d4.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9300c0b886e2055bc658ddc18e132f6a.png)
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解答题-证明题
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适中
(0.65)
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【推荐2】已知底面
是正方形,
平面
,
,
,点
、
分别为线段
、
的中点.
平面
;
(2)求平面
与平面
夹角的余弦值;
(3)线段
上是否存在点
,使得直线
与平面
所成角的正弦值是
,若存在求出
的值,若不存在,说明理由.
![](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/1ab738b69adbbb752d38411395ab8e8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c552df4af28e6a0a7cb993731958fddf.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/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f53330c107f8245290a5a42c3d356acd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57f9d682e5d3cc8573574d8d11636758.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50839c95d7a2adf8f0faf6ee182d20e0.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a4613db540c9cb6a9d7e963bf89c2a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21c133b31ab3c50dc87d80879bbb0633.png)
(3)线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d50703c46b6153945d718b198f03b4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a4613db540c9cb6a9d7e963bf89c2a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/924d32b574fe69e43724304cf39513e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d4838797cff70efabc1e8c1c005e3d6.png)
您最近一年使用:0次
解答题-证明题
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适中
(0.65)
名校
【推荐3】如图,在三棱柱
中,
,顶点在
底面
上的射影恰为点
,且
.
(1)求证:
平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4ef28bae91603373014bff6154c6fc2.png)
(2)求棱
与BC所成的角的大小;
(3)在线段
上确定一点P,使
,并求出二面角
的平面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36c4559d27e3905980d1a4f1856f07de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d76cef03e6b2d02024495a840ab451.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/15/6f972006-8d13-41ba-b697-50563636a049.png?resizew=177)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1c401f9dd333b36433b56d7aef1ffc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4ef28bae91603373014bff6154c6fc2.png)
(2)求棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
(3)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d1f2ff0805c573e3c1fc1720d4e531e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ee992e4455f983dcec7c98d0e51e194.png)
您最近一年使用:0次