如图1,菱形
中,
,
,垂足为点
,将
沿
翻折到
,使
,如图2.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/2/c6998d52-3ff4-4696-976c-faf7b9fe6c46.png?resizew=423)
(1)求证:
平面
;
(2)在线段
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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5b8b98b2f83279a49e94d9f48c5e6f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32c38dfd14dde969702dff97ef2270f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c771a4feb150ad9cff8d70431c97eb17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e92fed536087a6c2e8c44296b81a1d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1b48da67abdfa3f88dfb1819d3e2c8b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/2/c6998d52-3ff4-4696-976c-faf7b9fe6c46.png?resizew=423)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c1ddf0588b6b7c868afba00bb869f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65277734669566578cbb7d690bb200fb.png)
(2)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a21897349d3d7c94419692106887153.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7a407b262c22419f73396170ecdc849.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/719103f93166bab4828257608e641a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88adac398a2de2d407c0cb414e7b1336.png)
更新时间:2022-07-20 22:42:33
|
相似题推荐
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,等腰
与四边形
所在平面互相垂直,若
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3eb59251a61bd8374fcda5efee3b921.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/19/7d4a564c-a030-44f4-b964-6d89f98d4eb6.png?resizew=199)
(1)求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
平面
;
(2)若
,求四面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1a3b94566843e92ce775ff6bdf386fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef185a1b221d9a9b15cc548df459d511.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3eb59251a61bd8374fcda5efee3b921.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/19/7d4a564c-a030-44f4-b964-6d89f98d4eb6.png?resizew=199)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fc7991ea17d54ff5f4445ac5699463.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96a632f7a6a7a98525731156ea8c82d4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32c05247f6998d7a70d31d13be4148c.png)
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【推荐2】 如图,在四棱锥
中,底面
为平行四边形,
为等边三角形,平面
平面
,
,
,
,
![](https://img.xkw.com/dksih/QBM/2019/6/8/2221418489921536/2221897086279680/STEM/2188c642-1a66-4a8a-ba29-5dcccbc85af5.png)
(Ⅰ)设
分别为
的中点,求证:
平面
;
(Ⅱ)求证:
平面
;
(Ⅲ)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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/177678001b2ccde1db8f57fa5e017002.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b44f4120c94cb7176dc31fcac387b32e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/833cfda415649b832cc136caed392753.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0d5a2cd05e4476fc72271e8fdb59a9a.png)
![](https://img.xkw.com/dksih/QBM/2019/6/8/2221418489921536/2221897086279680/STEM/2188c642-1a66-4a8a-ba29-5dcccbc85af5.png)
(Ⅰ)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40fc2939eeeb58c6bd53921bc008147a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6fac1b61413574d7d4646bcc88881367.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/604c52089e01ac5ab3f14125f9b06de1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/852aabd89edffc1b94344ff3f1f31ccd.png)
(Ⅱ)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
(Ⅲ)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
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【推荐3】如图1,
为等边
的中位线,将
沿
折起,构成如图2所示的四棱锥
,其中
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/5/c29c4366-fb9c-4bba-adf3-d74c597d4dc3.png?resizew=405)
(1)求证:
平面
;
(2)若平面
平面
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9742a7f64ff91be02601331f4ef2bb4e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dd634589ddc99804a04a8c5aefaf944.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/5/c29c4366-fb9c-4bba-adf3-d74c597d4dc3.png?resizew=405)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6ae72f5e5891249caa10c43224da89c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/681a14aec64cda52d732cbd436fa589f.png)
(2)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6501f1c913a4ef64957a2f01ab5baa15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a28d6477c85c5a4ac410a884e92fbe53.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8be439d8369806e882a77dd96d3b5a2e.png)
您最近一年使用:0次
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解题方法
【推荐1】如图,在直三棱柱ABC﹣A1B1C1中,AA1=AC,且AB⊥AC,D,E分别为是A1C1和BB1的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/27/0c86252c-46b6-4380-9731-87c8a3b8815b.png?resizew=143)
(1)求证:A1C⊥平面ABC1;
(2)求证:DE
平面ABC1
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/27/0c86252c-46b6-4380-9731-87c8a3b8815b.png?resizew=143)
(1)求证:A1C⊥平面ABC1;
(2)求证:DE
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb31ef428bd9de9bc875b343feded3c7.png)
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【推荐2】如图,在四棱锥P-ABCD中,四边形ABCD是矩形,AD⊥平面PAB,PA⊥PB,E为AD的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/30/66cbce6b-e55d-4001-945e-9f7b11e267cc.png?resizew=145)
(1)若点M在线段PB上,且直线EM∥平面PCD,确定点M的位置;
(2)若
,
,求平面PCE与平面PAB所成锐二面角的余弦值.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/30/66cbce6b-e55d-4001-945e-9f7b11e267cc.png?resizew=145)
(1)若点M在线段PB上,且直线EM∥平面PCD,确定点M的位置;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bd50cf631e459b58b180cdf2f57844c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b5f2391d09eba3db2299f29d2ec2674.png)
您最近一年使用:0次
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(0.65)
【推荐1】如图(甲
,
是边长为4的等边三角形,点
,
分别为
,
的中点,将
沿
折成四棱锥
,使
,如图(乙
.
(1)求证:
平面
;
(2)求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04582116cd765fcc5a52f44279ad6c94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53502463cc76201000e02df314e58769.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53502463cc76201000e02df314e58769.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a15a004f7d47ed595f063e60075223a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04582116cd765fcc5a52f44279ad6c94.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/2/c18e53dc-69ff-432d-a6c5-57f5aa56192d.png?resizew=324)
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【推荐2】如图,在三棱锥
中,
平面
,
,
,
,E为
的中点,过点A作
,垂足为点F.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/9a9767d1-a732-4175-b7ca-6716e24b17d8.png?resizew=182)
(1)求证:
平面
;
(2)求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36c4559d27e3905980d1a4f1856f07de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bae7599ad243c12d94325ad917f0a44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/077c956ac0eb05cf120e14f17413dfa2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/187ed13a7bd532bd39af5e5ad7493a2c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/12/9a9767d1-a732-4175-b7ca-6716e24b17d8.png?resizew=182)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a22d6b860f06fe23618b0d3de6768fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
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【推荐3】在如图所示的几何体中,四边形
为矩形,平面
平面
,四边形
为直角梯形,且
,
,
,点
为棱
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/cc0d4ffb-d723-4c98-b5e9-935ab8d5f51a.jpg?resizew=198)
(1)求证:
;
(2)若直线
与直线
所成角为
,求直线
与平面
所成角的正弦值.
![](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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdb2dd10731b99c0f4f89ee957f8a239.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65096f2be416307cfd3941b32e033f0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/cc0d4ffb-d723-4c98-b5e9-935ab8d5f51a.jpg?resizew=198)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c013855f9a333862df79cd203604165.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2273ae1ee99cec9c1304323bc9ebf75f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79a97bb4dcfab4ec7539bc783d563c49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
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