如图,直三棱柱
中,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cdd80d2b2fba16ededd985bb8f2f162.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/608aacfb144413733af4c90d8f36f8d7.png)
是棱
上的点,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ef85b3e613e0fa8b414e9dc6036f8ca.png)
![](https://img.xkw.com/dksih/QBM/2017/5/7/1682053838675968/1684054064553984/STEM/1f90ddd4-93a6-430e-9333-755a303f894d.png?resizew=149)
(Ⅰ)求证:
为
中点;
(Ⅱ)求直线
与平面
所成角正弦值大小;
(Ⅲ)在
边界及内部是否存在点
使得
面
存在,说明
位置,不存在,说明理由
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cdd80d2b2fba16ededd985bb8f2f162.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/608aacfb144413733af4c90d8f36f8d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ef85b3e613e0fa8b414e9dc6036f8ca.png)
![](https://img.xkw.com/dksih/QBM/2017/5/7/1682053838675968/1684054064553984/STEM/1f90ddd4-93a6-430e-9333-755a303f894d.png?resizew=149)
(Ⅰ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
(Ⅱ)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4739afd7311501e948aa4e1e5c1cb17.png)
(Ⅲ)在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e21b3c5a71df7c74739468de3553057.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d14954e270de014a275fbc17fded838f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
更新时间:2017-05-10 17:19:40
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】类似平面解析几何中的曲线与方程,在空间直角坐标系中,可以定义曲面(含平面)
的方程,若曲面
和三元方程
之间满足:①曲面
上任意一点的坐标均为三元方程
的解;②以三元方程
的任意解
为坐标的点均在曲面
上,则称曲面
的方程为
,方程
的曲面为
.已知曲面
的方程为
.
过曲面
上一点
,以
为方向向量,求证:直线
在曲面
上(即
上任意一点均在曲面
上);
(2)已知曲面
可视为平面
中某双曲线的一支绕
轴旋转一周所得的旋转面;同时,过曲面
上任意一点,有且仅有两条直线,使得它们均在曲面
上.设直线
在曲面
上,且过点
,求异面直线
与
所成角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1277d620abbfa26fb39600e53e606d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1277d620abbfa26fb39600e53e606d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1277d620abbfa26fb39600e53e606d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fa13f27f92b55bd7ecd9d750f98ae99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1277d620abbfa26fb39600e53e606d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1277d620abbfa26fb39600e53e606d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eedd047376c4cf1b9992cd8e4fe20df2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33d7a5b312e3d789a1070000315d63b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0b4e60b50889c152c56fcf2d6ea35bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(2)已知曲面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7d96461d2b3421aed548b754637ca8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e81e59019989b7dc2fb59b037ef6e010.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13dea1bd3d0dd84b8b6f6ff634c5600c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44ddad9072eb1393ce15ca0627c941b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13dea1bd3d0dd84b8b6f6ff634c5600c.png)
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解答题-问答题
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解题方法
【推荐2】如图①,在矩形
中,
分别为
的中点,现将矩形
沿
折至
的位置,使得平面
平面
,
分别为
的中点,如图②所示.
(1)证明:
平面
;
(2)在线段
上是否存在点
,使得
?若存在,求出
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1da3d9bb8cb7672eec20e2d6070c12a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e582ef9086d16e76c804fb6f73b1664.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b25c5b6c06e1d1a0061a6fc28111e7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb5a68a008a22d5a8cea5fe8dcf31e10.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77c605493ee5aed9e48f8a6b193fa7bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f0db1e32fcbc3f7cad3472ef5fbad0e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/14/856bfd64-3a37-4da9-9cd2-ce4c8fd79854.png?resizew=324)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96b8c2721ada247b03f41f328539b301.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/193b5b41994c2a4dfa5bb0bc984061cc.png)
(2)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9dd96e8e48c343bad62a6b4fb14322f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea4de9b7f06a2577f24cafe8e6f70377.png)
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(0.65)
名校
解题方法
【推荐1】直三棱柱
中,
,E,F分别是
,BC的中点,
,D为棱
上的点.
;
(2)是否存在一点D,使得平面
与平面
的夹角的余弦值为
?若存在,说明点D的位置,若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09bdbf17f7bb0e70a339b4a1971d5c0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a7077d7e5ceacb3cd5d7338a8da069c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8689d619c2508c9000531fc1b8f1f21c.png)
(2)是否存在一点D,使得平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1694e2395aef476b9952f92ca72ba56f.png)
您最近一年使用:0次
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解题方法
【推荐2】已知直四棱柱
中,底面ABCD为菱形,E为线段
上一点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/cdcb8e55-a683-4770-9c0d-b737c88641e9.png?resizew=167)
(1)证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
平面
;
(2)若
,则当点E在何处时,CE与
所成角的正弦值为
?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cfbc0b5a8fbde804bd8425a4b76d207.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/cdcb8e55-a683-4770-9c0d-b737c88641e9.png?resizew=167)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a935b7d21a103a264b6e96ecf82dbe4a.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8923f867767455ab4ca0913daa888ed6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb8f6ab40dbad20c5b2527d0d4e11ef9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a4e6eb3663870ed202cc208eaf239dc.png)
您最近一年使用:0次
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适中
(0.65)
名校
解题方法
【推荐3】如图,在多面体
中,平面
平面
,四边形
为正方形,四边形
为梯形,且
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbc1fc9975e98e47cb48521ab7a86dc6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/7/451f87ab-eb97-422f-baf2-e810e5555ca1.png?resizew=231)
(1)求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fbee06d305abf6692125513dc3757f9.png)
(2)线段
上是否存在点
,使得直线
平面
?若存在,求
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9367449a5847eade07e69f4feddcb027.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ecc1cb55a57dde481f8dd07ab150676.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6dceb5cc71fc50f20649f6b9535fd914.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbc1fc9975e98e47cb48521ab7a86dc6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/7/451f87ab-eb97-422f-baf2-e810e5555ca1.png?resizew=231)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fbee06d305abf6692125513dc3757f9.png)
(2)线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/932a04304f2d4975955d4baabb2deeea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6114761b369162cda06f08e31c23fc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/258ed4f5282317bb067a41104d559222.png)
您最近一年使用:0次
解答题-问答题
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适中
(0.65)
【推荐1】如图9-6-6,矩形ABCD中,AB=1,BC=a,PA⊥平面ABCD.
(1)问BC边上是否存在Q点,使
⊥
,说明理由.
(2)问当Q点唯一,且
时,求点P的位置.
(1)问BC边上是否存在Q点,使
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45e09c5410984d89f379f9619d073ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3004d331d39b1a366d30fe725f8ad773.png)
(2)问当Q点唯一,且
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ea9330ee3b685f04acc19c8d20e7e27.png)
![](https://img.xkw.com/dksih/QBM/2011/10/14/1570316276137984/1570316281790464/STEM/1d3f36c90d4e47cda618e0e042fa7025.png?resizew=87)
您最近一年使用:0次
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适中
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解题方法
【推荐2】1.如图所示,已知平行四边形
中,
,
,
,
,垂足为
,沿直线
将
翻折成
,使得平面
平面
;连接
,
是
上的点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/b5491256-fa9a-451f-a754-8776122f48be.png?resizew=494)
(1)当
时,求证:
平面
;
(2)当
时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d79e7020414add95907e061df505ef0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6da5fbf1298eca6853f9febfd4a07440.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e3f5dc11efe60b4fd9a13b1d6b83842.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad09a769a75b107390b9eeccc929f761.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cb0a272d6917c569c36b60dd9ec8094.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73612d2cce34e663255c76ccab2d892a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6bfad3f7e65188bcf7f62ea5acdbf4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab41cce6eb2d3058a644314865d16548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab41cce6eb2d3058a644314865d16548.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/19/b5491256-fa9a-451f-a754-8776122f48be.png?resizew=494)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d07d047a406fbf8cd353a5aed9bf0c85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e245440d3761fb4217eaa8dc303fa288.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47ce36044e81456a40b5f63749c814e5.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52ddbc03b14bc6a863989f2ab6048e3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/471c511dc9f95ac5eb4784a105aee9e0.png)
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
是矩形,
,侧棱
底面
,点
为
的中点,
与
交于
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/1/91ff15b4-54c3-437f-b1f4-8d6f2971ef7a.png?resizew=245)
(1)求证:
平面
;
(2)求平面
与平面
的夹角的余弦值;
(3)若
为棱
的中点,则棱
上是否存在一点
,使得
平面
.若存在,求线段
的长;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f95bc3dddefd4d0fe11c2c0277a061f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10c83f8945042b9c8fb2fbdac9308d62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/167d31eb8432b5c0364316e5048c23dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7494938c7eb96bb504e15bcabced87b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/1/91ff15b4-54c3-437f-b1f4-8d6f2971ef7a.png?resizew=245)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28f79db7c270b6ff9fb0a538ee201cfe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9c9cfa597b444b5c9dbae7a825a695.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf4c26f3f4d96117f087400a0f32ece8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9c9cfa597b444b5c9dbae7a825a695.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c2bc5e50b8dfa02601c70822252854a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a6e2867f32d3f1c3cd36cd3a11a8580.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6deecf9ccb7b7879455050633219e09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3808695d7a8a90f6d4c0d55f7166ad19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fddbb7f29e8672f34941fe70b0a1e45f.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
【推荐2】如图,在四棱柱
中,侧棱
底面
,
,
,
,
,且点
和
分别为
和
的中点.
![](https://img.xkw.com/dksih/QBM/2020/8/12/2526506069188608/2529263638061056/STEM/76785987-6a8e-4365-98ac-10df892766c5.png?resizew=244)
(1)求证:
平面
;
(2)设
为棱
上的点,若直线
和平面
所成角的正弦值为
,求线段
的长.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1ecf072589c0f901d92f6bda111d841.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36c4559d27e3905980d1a4f1856f07de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c9d5815dc775d5a5810fff0b016a8d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/70c2888dad200ebe6cbc60b7a680ad6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7f6f93171329d508d491143b9d71f7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e3334853138fb74687d66b1e45f2fd9.png)
![](https://img.xkw.com/dksih/QBM/2020/8/12/2526506069188608/2529263638061056/STEM/76785987-6a8e-4365-98ac-10df892766c5.png?resizew=244)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edcf19a7f0dd0cdf59516ae585025110.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5d8e33929752b1cb4dd36ee9b98b45d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce1b066f8869d0ff4513f7a99745125.png)
您最近一年使用:0次