如图,在正四面体OABC中,E,F,G,H分别是OA,AB,BC,OC的中点.设
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/21/02791232-a05a-4f00-b1c3-e7cdb8e5d12a.png?resizew=169)
(1)试用
,
,
表示
;
(2)若正四面体OABC的棱长为6,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91a9cb32a25c2a8bb99f75633b4cd5ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/049131856ba841523793ee3d83099014.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1eca8aa7145b2327dbccba46da05bb86.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/21/02791232-a05a-4f00-b1c3-e7cdb8e5d12a.png?resizew=169)
(1)试用
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb80eb942aafb194fadc473776f35b1d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/433b94c39737727e53468df419d8314a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb573cc0f30d5c32cdad1510793f0e7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cfa18a71378395f3153cf50f04c2e20d.png)
(2)若正四面体OABC的棱长为6,求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e271fc705fed1bd4ddb4eac3764e2c1.png)
更新时间:2022-09-19 22:34:09
|
相似题推荐
解答题-问答题
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适中
(0.65)
名校
【推荐1】如图,在平行六面体.![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b125fafb16819e103d49b1374932abe4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8689281b26bb0323c4f8055cd672d38.png)
,设向量![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4558eb885fab4c2047ac078135fae315.png)
(1)用
表示向量![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbd7bd26cc18343c5c3fdf84333c480e.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b125fafb16819e103d49b1374932abe4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8689281b26bb0323c4f8055cd672d38.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4d13ecb54b1006051d2561327aa4755.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4558eb885fab4c2047ac078135fae315.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/28/96cc5637-7f35-4cd2-8f9c-c528b9471819.png?resizew=169)
(1)用
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3352ef5f607b600467e786b4e0654e32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbd7bd26cc18343c5c3fdf84333c480e.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6442fa9c249ccfdc412347a6b772b218.png)
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适中
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解题方法
【推荐2】如图,矩形
是圆柱
的轴截面,
分别是上、下底面圆周上的点,且
.
;
(2)若四边形
为正方形,求平面
与平面
夹角的正弦值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abbe2aba242716238b79c46bb1f40e88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a25ac7d48390e804f9d11597b26f14a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1089f40864a8ec79bf544ab7ff1cc43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a2612c3ed33135b60b5a08c173c9f84.png)
(2)若四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2330c01a4d2b5b20f106e3e48834d5c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20af148464904e21f4374cc8fb886fba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
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解答题-问答题
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适中
(0.65)
【推荐1】如图所示,已知空间四边形
的每条边和对角线长都等于1,点
分别是
的中点,计算:
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/5/4cfc3d7c-37b4-4a11-95cb-d8ebb1ab5fce.png?resizew=132)
(1)
;
(2)
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b199a99e53d67ff4abf233930961a29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/868a68302dfab497e705816c2b1c9708.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/5/4cfc3d7c-37b4-4a11-95cb-d8ebb1ab5fce.png?resizew=132)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/210fdc99a8e55efb1829b0b095389315.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6610089a85e4dc5b1c57b588034d28c7.png)
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解答题-证明题
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适中
(0.65)
【推荐2】如图,在平行六面体
中,
平面
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/21/e0bb10cc-07f5-4c60-95df-48e535cec68f.png?resizew=171)
(1)求证:
;
(2)线段
上是否存在点
,使得平面
与平面
的夹角为
?若存在,求
的长;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ddbb0422a136f45653c8c369f2d75fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4615b646e7f1d30265d3fdd4f8439fe3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f02723217767fbe9da511292d1be7ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83472c2139c75eea390cfc0e1104e296.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/21/e0bb10cc-07f5-4c60-95df-48e535cec68f.png?resizew=171)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbeb1554fc1cec56b983a08e9dc52c85.png)
(2)线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f66fb71b75b63594ebeeeebd1963eed5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65277734669566578cbb7d690bb200fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15615de1a6df206dbd081251f676578e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15dc61d5de97b5a40be925b278ae494c.png)
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解答题-证明题
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适中
(0.65)
【推荐1】在正四面体
中,
,
,
,
分别是
,
,
,
的中点.设
,
,
.
![](https://img.xkw.com/dksih/QBM/2021/12/4/2848404014669824/2870450356477952/STEM/094bb8746cf9483fb4cf85ff3d19554e.png?resizew=190)
(1)用
,
,
表示
,
;
(2)求证:
;
(3)求证:
,
,
,
四点共面.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3241d7fedd89d85711acd7a2635298af.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/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef4113c492885ba7c47fe42ac792578f.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/828628c0876b45381c9a0edeb0fec236.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14390e9b6b44472bdc7a131133ab39b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87cd14dfc0024459f9d8e594c95c5106.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e07dcf0b16163e0e0e0c0f248466ee7e.png)
![](https://img.xkw.com/dksih/QBM/2021/12/4/2848404014669824/2870450356477952/STEM/094bb8746cf9483fb4cf85ff3d19554e.png?resizew=190)
(1)用
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64c5562bd4d1b54424330cb6329cd79d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b45ba716f03748c19b7ce2f99af536ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73a0b19e69be46452425916a0fcb49c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae54940f33b8714da5fe3b7546f8b3dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e74c0f207612e015857b78b99db483e4.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c31c9f6ee41257798d7740a2043e108.png)
(3)求证:
![](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/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
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解答题-问答题
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适中
(0.65)
【推荐2】如图,在三棱台
中,
,
,
,设
,
,
,以
,
,
为空间的一个基底,求直线
,
的一个方向向量.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/929fddde7318f74379bb91e682f8568f.png)
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/4/59b2f058-b990-4e73-aac3-5d91d39c4f7d.png?resizew=156)
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