直三棱柱
中,
,D为线段AB上一动点.
(1)当D为线段AB的中点时.证明:
平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f62fd0b510920be6bc60d170c3ff3da3.png)
(2)当
时,求直线
与平面
所成角的正弦值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f99985b30b28a04db32fe62abe5d1f7c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/26/11220658-40be-4aa5-b355-6540f8ac33fe.png?resizew=147)
(1)当D为线段AB的中点时.证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4557a368725226f2c8ea2efb7d30e478.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f62fd0b510920be6bc60d170c3ff3da3.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6305ae5c06c041032bd65b16162c4a68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1859959fdb4c5edd8056893f94a10a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbc7e774e4ae40c23bf4ceed179230ca.png)
更新时间:2023-11-05 22:55:48
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
【推荐1】如图甲,设正方形
的边长为3,点
分别在
上,且满足
,
.将直角梯形
沿
折到
的位置,使得点
在平面
上的射影
恰好在
上,如图乙所示.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/23/17fd686d-af75-41bd-832a-60d766f31fdf.png?resizew=305)
(1)证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e26d9636ad77369535852c6e4493446a.png)
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/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5c4cd264c97c1f261229925cc5a6761.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a02c25b95e61557eec096de150ab873f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87ef0a99a25b115e054452abff205544.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/946c16d99496d31ce4d87301a4793393.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6ccd49a0c3ccd22943c15ed7bf0f4c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a6480f384476190883f06c0289c7519.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/23/17fd686d-af75-41bd-832a-60d766f31fdf.png?resizew=305)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e26d9636ad77369535852c6e4493446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895d6f710d5f67e1d4c7408d50d77281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbcfe92b25904211a9d1ebc69f07f196.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c503159141b3055c64ef6f27cacfe8e.png)
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名校
【推荐2】如图,在三棱柱
中,D是
的中点,E是CD的中点,点F在
上,且
.
平面
;
(2)若
平面ABC,
,
,求平面DEF与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e26d9636ad77369535852c6e4493446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42a9b4db32c930bc04606ddc9f23bbc0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06222ee533c2484ab25321a6abbf98cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5845ccc0d735dc14c92a8926d9b1def6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36c4559d27e3905980d1a4f1856f07de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2af2626608f61a4cfbb86494bd6df0e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b1f68454096da710903e9693c7f2015.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
【推荐1】如图,在四棱锥
中,
,底面
为平行四边形,
,
.
(1)证明:
;
(2)若
,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/24beb104b3b166ad5c0a28f9037e0fd5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf958c008f9983aa2d16714a3574c936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c4e4a162f12d12a082b8d8fdd1aeab9.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b07e317ffe7859e81b42ef4970e344a.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba4c15fb8fc3239d45bd4e7d8971f58e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐2】如图,在四棱锥
中,四边形ABCD是矩形,平面
平面ABCD,
,E是SB的中点,M是CD上任意一点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/22/f228ccfd-2503-473a-b729-1ea4c6802627.png?resizew=171)
(1)求证:
;
(2)若
,
,
平面SAD,求直线BM与平面SAB所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/877582b5387278008d14fe5932622fe7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e270a358087318deb85f1e955f14375.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/22/f228ccfd-2503-473a-b729-1ea4c6802627.png?resizew=171)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61c0628fd53118477b46fd8172c7dbfd.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66f60936f1fdbbb23380a600e8c56662.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65204d1dd2bca2e33c2a3f3d9d22655e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd0285afe567ca0b32f0ccafc30167cc.png)
您最近一年使用:0次