在正三棱锥
中,
,点
在线段
上.过点
作平行于
和
的平面
,分别交棱
于点M,N,O.
(1)证明:四边形
为矩形;
(2)若
,求多面体MNPOBC的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4357d5744046d4d44abb09e1ee35fcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57c6b0a6cb307c4c02f503831862f7d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75d0abaa4e36f9675f849c300dff7056.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/7/b0c010cf-ca18-4bd2-8d6f-4ade61823669.png?resizew=130)
(1)证明:四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82ee04f40f79d73e803b91530e208330.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8de90eb325adb8122baa14c7e49f703.png)
更新时间:2023-07-06 07:47:17
|
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,圆台
的轴截面为等腰梯形
,
圆台
的侧面积为
.若点
分别为圆
上的动点,且点
在平面
的同侧.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/25/76104524-00fb-4979-a20a-22b67a237473.png?resizew=176)
(1)求证:
;
(2)若
,则当三棱锥
的体积取最大值时,求多面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e65ac334119ccd6204402a7aba29a55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fee8f3cec7f73237eeb6119505b624.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab97fba8ff6395cadbabc8f72a1ea271.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e65ac334119ccd6204402a7aba29a55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2804428c789eff0c917c50ac9aae0961.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39acab3cfb59bfc9591371721ab01d93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d096cd7bd8a5a2219fd7dd166bbb8460.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39acab3cfb59bfc9591371721ab01d93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fee8f3cec7f73237eeb6119505b624.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/25/76104524-00fb-4979-a20a-22b67a237473.png?resizew=176)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/143bc52bf615596ee5d707e8c9592018.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b54c1e51d642b56e85c4fbf04c31b270.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31c380651bb919db7111650d73a46c01.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e10df339e7f7055c5699236359ceaea.png)
您最近一年使用:0次
【推荐2】如图,某种水箱用的“浮球”,是由两个半球和一个圆柱筒组成.已知球的直径是
,圆柱筒长
.
(1)这种“浮球”的体积是多少
(结果精确到
?
(2)要在这样10000个“浮球”表面涂一层胶质,如果每平方米需要涂胶100克,共需胶多少?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dd6f4250ca6b1b9bce234a01f00d44d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c78d0ab561d0c9bb9099772c596af8bf.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/17/2986e8ea-ffad-4b19-9286-77916104c873.png?resizew=128)
(1)这种“浮球”的体积是多少
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc6d1d99afa158b4ba4fc0dae562fcc1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71afb9adfd15cf230ee201f170826799.png)
(2)要在这样10000个“浮球”表面涂一层胶质,如果每平方米需要涂胶100克,共需胶多少?
您最近一年使用:0次
解答题
|
适中
(0.65)
名校
解题方法
【推荐1】在直三棱柱
中,
是
的中点,
是
上一点.
![](https://img.xkw.com/dksih/QBM/2017/6/4/1701842468175872/1702493218242560/STEM/e0ae7493b9ef44b3bac9ea196015e692.png?resizew=253)
(1)当
时,证明:
平面
;
(2)若
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ede6a60cad0e0b58e1549fda6e085719.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02002aab339b4abe6bbe289524309b7c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/764509115979e9958101808383672ec0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b094e639c2b31dc54b1b3e6456e77843.png)
![](https://img.xkw.com/dksih/QBM/2017/6/4/1701842468175872/1702493218242560/STEM/e0ae7493b9ef44b3bac9ea196015e692.png?resizew=253)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0042fbd04367d0df0fba2f59de72aa26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96c117069912c61e8f6eb6a687597547.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd4bb9571b33d88f735fe6dc8fe41209.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63611a0a2d63593cf1d056d41ae885da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65121aa696e4ec7b9d0c7143418227c0.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
解题方法
【推荐2】如图,正三棱柱
所有棱长都是2,
是棱
的中点,
是棱
的中点,
交
于点
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/10/87884f75-6dfc-4a0f-b0f1-33b691aaf210.png?resizew=206)
(1)求证:
平面
;
(2)求二面角
的余弦值;
(3)求
与平面
所成的角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10d8eb4a9f462ca0c1d49c3fe91e720d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/10/87884f75-6dfc-4a0f-b0f1-33b691aaf210.png?resizew=206)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f4c3f9dd5d0343597a7f58a1989b537.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1989198cafd20bdd155114749660e47.png)
(3)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.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】如图所示,在梯形
中,
,
,
.四边形
为矩形,且
平面
.
平面
;
(2)若直线
与
所成角的正切值为
,点
在线段
上运动,当点
在什么位置时,平面
与平面
所成的锐二面角的余弦值为
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f18f1b5ebe17b068fe79bdf30d6effc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5b0382c28547d3834ca71f3f0677695.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bbc56d42b003cbcb1fbe5c50e55b26b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac0b72906641ed13716cfbce50923282.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a09d9d486b7f91ba933210dd013a7f2c.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/619096595112f0340a43b756e114dd3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daf2f0df53aa68c9c334165034788166.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2db1674add0f4a1a24f5ed893b1c5d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4e108d5c61e85e0741ec2c484fc5768.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,在四棱锥
中,
平面
,底面
是直角梯形,
,且
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/9710a153-ae34-4fce-b2fc-f75bbccf0165.png?resizew=160)
(1)求证:
;
(2)求二面角
的余弦值;
(3)在线段
上是否存在点
使得![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
平面
?若存在,请指明点
的位置;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/804a81583da250a09ebc0dd16fb7b7b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ba02caa818e213ed407203b8ddb8075.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/9710a153-ae34-4fce-b2fc-f75bbccf0165.png?resizew=160)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7bd02e0adeae92ba9526261b1baf797.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42f4096ff62b4f29932cd8c6eef661a3.png)
(3)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69d2b798744645af88a4fa411344a83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46e2da608b66c9aee03e2503388ba4fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐2】三棱锥
(如图1),O、E、F分别是线段
、
、
的中点,G是
中点(如图2).
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/2/f22d45ca-8749-418b-a893-3d022e63b5d0.png?resizew=422)
(1)若
,
,求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b5f215a42c4b7078d8d65923eb9980e.png)
(2)求证:
//平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4357d5744046d4d44abb09e1ee35fcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828628c0876b45381c9a0edeb0fec236.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/2/f22d45ca-8749-418b-a893-3d022e63b5d0.png?resizew=422)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9953b7b5c647641edbec4c2ab90a65f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b5f215a42c4b7078d8d65923eb9980e.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63e36329f5e0979f5ee776ac5d06327.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5f92c5ae6d8df4bf91d9ba6664b26b9.png)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐1】如图,四棱锥
的底面是边长为4的正方形,四条侧棱长均为
.点
,
,
,
分别是棱
,
,
,
上共面的四点,平面
平面
,
平面
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/f2269626-1bc4-422c-a06b-68a12526c3cc.png?resizew=198)
(1)证明:
;
(2)求
与面
所成角的正弦值;
(3)若
,求四边形
的面积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e20838e72faf737614d76fcee82ab6c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.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/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90ecdaab3160da098a8f5ca525192bc4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08f8b463fcecf0a757f386db56e074d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a74a1536fb7546c769cdf684181b8997.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/f2269626-1bc4-422c-a06b-68a12526c3cc.png?resizew=198)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e515b0bfadf81e7e0fc57e333c03047.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a74a1536fb7546c769cdf684181b8997.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2736c6f5b1436863983cf84cb3d27f88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a74a1536fb7546c769cdf684181b8997.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,在边长为4的等边三角形
中,平行于
的直线分别交线段
于点
.将
沿着
折起至
,使得二面角
是直二面角.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/11/17f50144-b828-4c3c-888e-823b5ef2df0e.png?resizew=170)
(1)若平面
平面
,求证:
;
(2)若三棱锥
的体积为1,求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7dec2ca6438c82b43f746057d8129885.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7789a500686c7a73770404ead6af0590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98013a5042685a1db94249e70c62c09a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e3bacc06686947aeaf85e71b2e46aaa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e11ad0587f9c42941320be63f4b1ad7.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/11/17f50144-b828-4c3c-888e-823b5ef2df0e.png?resizew=170)
(1)若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee8d2d20b2d2d56ec35cd5c6bbfbc4ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6097e56f0e6cb49dfea1b5ba6805c61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edbf6462666c8015e7de28e344af30b2.png)
(2)若三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa7d8ebbebd9a58d2cce6e662a34b23c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/790f2ff63916dc8788b7c1fab39b4dde.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
【推荐3】如图,在三棱锥
中,
平面
分别为
的中点.平面
与平面
的交线为l.
;
(2)求平面
与平面
的夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf63858895040e7ce2b838057267151f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebf43f0530ae36096a0c1acdfd793845.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e41f245930493e628ddf029fcf653b8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e7344dca1e40bf072371ddd5640111.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffe8a84ca3a13f82aff1a022edc66065.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adbe5de909b009cd31d076b19faa579f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f80ee756cb5e4b3cb5f0ddc53d75647e.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05479863cf9f41e2ad9f843ea740a3c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffe8a84ca3a13f82aff1a022edc66065.png)
您最近一年使用:0次