名校
解题方法
1 . 如图,已知正方体
的棱长为1,若点E、F是正方形
内(包括边界)的动点,若
,
,则下列结论正确的是( )
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/8/3801d1a4-c7a6-4c1b-aceb-8a773a514f9f.png?resizew=167)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/707a18a1cb508d28a73f95d41d1a89ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5621c78ba894e47b6161e27a664093a0.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/8/3801d1a4-c7a6-4c1b-aceb-8a773a514f9f.png?resizew=167)
A.点E到![]() ![]() |
B.点F的轨迹是一个圆 |
C.![]() ![]() |
D.直线![]() ![]() ![]() |
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名校
2 . 如图;正方体
的棱长为2,
是侧面
上的一个动点(含边界);点
在棱
上;则下列结论正确的有( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3da8c338342e38c9aa3f274c053fd5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5aca256a2888582d7691ce62453a49bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20ecac2dad4cffdd971fd23deacff3fc.png)
A.若![]() ![]() ![]() ![]() |
B.若![]() ![]() ![]() |
C.若![]() ![]() ![]() ![]() |
D.若![]() ![]() ![]() ![]() |
您最近一年使用:0次
2023-07-05更新
|
1067次组卷
|
3卷引用:重庆市巴蜀中学校2022-2023学年高一下学期期末数学试题
名校
3 . 在三棱锥
中,
.记二面角
、
、
的大小分别为
、
、
,V为三棱锥
的体积,则下列结论正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1e54d5d705db6825f987cb2dbf11702.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12a4bddf1ea3c5d37f2233a4821909e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/850319b7098a23b859791d7da3e63e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a438393ddfc7da1804baf4932442bb35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e20f37e376b5392f51bb95aff3eaaa99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/104b5a3aca3b79e21a579de54e96c744.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbc663d6d89b3d2ccea5d63849b9e20b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
A.![]() |
B.![]() |
C.![]() |
D.![]() |
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解题方法
4 . 《九章算术·商功》:“斜解立方,得两壍堵.斜解壍堵,其一为阳马,一为鳖臑.阳马居二,鳖臑居一,不易之率也.合两鳖臑三而一,验之棊,其形露矣.”即将底面为长方形且有一条侧棱与底面垂直的四棱锥称之为阳马,将四个面都为直角三角形的四面体称之为鳖臑.如图所示为鳖臑
,
平面
,
,
,
分别在棱
,
上,且
,
.若
,则三棱锥
外接球的体积为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6a94d59dee2d5a8f0425b64b2083825.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9c439e4e4e48b17e19e666d892216fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.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/95226c64f0afdaa10b95ec097a0720ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a392d05d3cfcbb438569b1ea9980dc2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82959bc6a8397312ff9e9cee81c090bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/597ca27ab3f3d2975779f7191cb0db58.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17e6476d3b1cc89d23dbe7a597ef980d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10026cc1f29356e4f97f14daa4814145.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/6/f12eb090-36ff-4265-a83b-3b76f31bb3ed.png?resizew=126)
A.![]() | B.![]() | C.![]() | D.![]() |
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5 . 如图,在矩形
中,
,
,
为
的中点,现分别沿
、
将
、
翻折,使点
、
重合,记为点
,翻折后得到三棱锥
,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1507da3daed983c2f355d4caebb66d72.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/941eba4dbc1094107e1eeb02c8d8cd56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/613dedf2d90e58591b7ac4a250ac7b5d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6830ebecddbd9759be626289c408e4f3.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/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/6/77035ad7-7ea5-4767-b661-3cf6bfb181f4.png?resizew=334)
A.![]() ![]() |
B.三棱锥![]() ![]() |
C.直线![]() ![]() ![]() |
D.三棱锥![]() ![]() |
您最近一年使用:0次
2023-07-03更新
|
893次组卷
|
2卷引用:重庆市主城区七校2022-2023学年高一下学期期末联考数学试题
名校
解题方法
6 . 如图,正方体
的棱长为2,点
是线段
的中点,点
是正方形
所在平面内一动点,下列说法正确的是( )
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/21/fa33e3f5-16ea-4dd9-ad16-6517766084f3.png?resizew=174)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22adbc0da438220f9cace11b629d799b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82b724168afaee2ecddf97257180be18.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/21/fa33e3f5-16ea-4dd9-ad16-6517766084f3.png?resizew=174)
A.若点![]() ![]() ![]() |
B.若点![]() ![]() ![]() ![]() |
C.若![]() ![]() ![]() ![]() ![]() |
D.若点![]() ![]() ![]() ![]() |
您最近一年使用:0次
7 . 在正方体
中,点P在线段
上运动,则下列结论正确的有( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7f6f93171329d508d491143b9d71f7b.png)
A.直线![]() ![]() |
B.三棱锥![]() |
C.异面直线![]() ![]() ![]() |
D.直线![]() ![]() ![]() |
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8 . 在长方体
中,
,
,
为棱
上的动点(不包含端点),则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7d64fc81c857b124268609a8beb77b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
A.四面体![]() ![]() |
B.直线![]() ![]() ![]() |
C.存在点![]() ![]() ![]() |
D.存在点![]() ![]() |
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解题方法
9 . 为了求一个棱长为
的正四面体的体积,某同学设计如下解法.
解:构造一个棱长为1的正方体,如图1:则四面体
为棱长是
的正四面体,且有
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/16/6db5d8bf-a942-4eb1-b74e-0d41be5b6734.png?resizew=583)
(1)类似此解法,如图2,一个相对棱长都相等的四面体,其三组棱长分别为
,
,
,求此四面体的体积;
(2)对棱分别相等的四面体
中,
,
,
.求证:这个四面体的四个面都是锐角三角形;
(3)有4条长为2的线段和2条长为
的线段,用这6条线段作为棱且长度为
的线段不相邻,构成一个三棱锥,问
为何值时,构成三棱锥体积最大,最大值为多少?
[参考公式:三元均值不等式
及变形
,当且仅当
时取得等号]
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
解:构造一个棱长为1的正方体,如图1:则四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68ac02c2f91cadb1e328bc6ab9b9c491.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6f878ffcff2ca25a434cbeea7d5c841.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/16/6db5d8bf-a942-4eb1-b74e-0d41be5b6734.png?resizew=583)
(1)类似此解法,如图2,一个相对棱长都相等的四面体,其三组棱长分别为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2967337e3fcb228dded64ab0c41a17e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50690dab38f4512eb72e18b7f86cf6f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4056761b8f826eeb6ad8c9a151d3c9c.png)
(2)对棱分别相等的四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c220eadc312101e2fb89dfe920f7b30d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7de966c316db1013defc56372fcf814e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8d2530e7023b2345c651e8f53629ff1.png)
(3)有4条长为2的线段和2条长为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
[参考公式:三元均值不等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ffb6b373d2e672bb2afc8de547861a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4849ff71159df2bb9099b26065d81e1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44acc0ee22dc4b7750e8be825e7c1355.png)
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2021-07-15更新
|
814次组卷
|
2卷引用:重庆市西南大学附属中学2020-2021学年高一下学期期末数学试题
名校
解题方法
10 . 如图,在七面体
中,四边形
是菱形,其中
,
为等边三角形,且
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/0f65797e-36c7-4564-b34c-13f588576be7.png?resizew=172)
(1)证明:
平面
;
(2)求平面
与平面
所成的锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6906f59d09ce31956d6f5ea2b23fc77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50a946d10d27eeb8726284e02d430522.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf4dc4d7d30af1cdce660795e0fd7d7c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/26/0f65797e-36c7-4564-b34c-13f588576be7.png?resizew=172)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ffe8a84ca3a13f82aff1a022edc66065.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14eec658f69c267a70c1e8f9b744e282.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
您最近一年使用:0次