在直三棱柱
中,平面
平面
.
(1)求证:
;
(2)
,
,
为
的中点,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21dee56b9f36ba8f76fe67b76383636b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac61c24f99a4e466f1e2ea011893866.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/15/b0a719ac-f72f-43a6-b8ad-a1c78199071c.png?resizew=137)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/209acf15985d1ea1ad86fc4a37e38c0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8d927585a17c2e98ef7d5a9589a26ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f1f229274a6e17977cc047814212589.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0830c440cb5f1b816d17dcdebdba71a3.png)
更新时间:2023-10-24 20:55:33
|
相似题推荐
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐1】在四棱锥A-BCDE中,直线AB⊥平面BCDE,底面BCDE是梯形,BC//DE,BC⊥CD,CD=DE=
BC=2,F是边BC的中点.
![](https://img.xkw.com/dksih/QBM/2022/1/21/2899509594611712/2904969320579072/STEM/1c9dbe70-09e8-480b-8bcd-825fae63c1d8.png?resizew=199)
(1)证明:AE⊥CE;
(2)若平面ADF与平面ABE所成二面角为45°,求直线AD与平面ABE所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://img.xkw.com/dksih/QBM/2022/1/21/2899509594611712/2904969320579072/STEM/1c9dbe70-09e8-480b-8bcd-825fae63c1d8.png?resizew=199)
(1)证明:AE⊥CE;
(2)若平面ADF与平面ABE所成二面角为45°,求直线AD与平面ABE所成角的正弦值.
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【推荐2】正方形
的边长为
,
分别为边
的中点,
是线段
的中点,如图,把正方形沿
折起,设
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/29f7d920-dada-4470-a413-98685f17b0e5.png?resizew=184)
(1)求证:无论
取何值,
与
不可能垂直;
(2)设二面角
的大小为
,当
时,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a373959bb9026f8a09845c0b828bf82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11944f055fd806016ae3576019d4bf30.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/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69abb300ce1514bd0ec9875ffbb54b7f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/28/29f7d920-dada-4470-a413-98685f17b0e5.png?resizew=184)
(1)求证:无论
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
(2)设二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cc6254fdf3ab25161b65f5c86c6c42d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6581916f5a65edfea257c804efee007e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d3362bb52fd689fb2586b1ccf351acb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98bb18a6e86849928dc217fb90810cb4.png)
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【推荐3】如图,在三棱柱
中,
,
,
平面
,
,
,
、
分别是
、
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/29/86e90f69-039e-4d39-a48c-3f3ded9c3382.png?resizew=156)
(1)证明:
平面
;
(2)求
与平面
夹角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f7bfdfe50a0c6be70b73a0f86b061a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00ee347187fbbfe9e8a6faf286795d79.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4560fa4ad459b58b723c74bd24e51ebf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d70dc2c20619a4fc12a0cfda59af5b69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31ddba26bcc8599e80d327351f1fa6a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/29/86e90f69-039e-4d39-a48c-3f3ded9c3382.png?resizew=156)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07b7903de4be7d5dc1175cfbf6e8da9f.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce6c0e9de83f2e64ae33609fc08459d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
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解题方法
【推荐1】如图,直四棱柱
的底面是菱形,
,
,
,E,M,N分别是BC,
,
的中点.
平面
;
(2)求点C到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e55a2310cbba5e050488cd9296eb195d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6906f59d09ce31956d6f5ea2b23fc77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10d8eb4a9f462ca0c1d49c3fe91e720d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b77b6829b026d38bde776e2993e3e9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a4c87f4da030d05da7c0fa59384743e.png)
(2)求点C到平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb5a463a03c549b0dba6d90e7f16a2af.png)
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解答题-证明题
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解题方法
【推荐2】如图,在四棱锥E-ABCD中,底面ABCD是正方形,AC与BD交于点O,EC⊥底面ABCD,F为BE的中点.
![](https://img.xkw.com/dksih/QBM/2016/5/9/1572622890278912/1572622896037888/STEM/6ace57c61a194ad0a59da7522fee9335.png?resizew=190)
(1)求证:DE//平面ACF;
(2)若AB=
CE,在线段EO上是否存在点G,使得CG⊥平面BDE?若存在,请证明你的结论;若不存在,请说明理由.
![](https://img.xkw.com/dksih/QBM/2016/5/9/1572622890278912/1572622896037888/STEM/6ace57c61a194ad0a59da7522fee9335.png?resizew=190)
(1)求证:DE//平面ACF;
(2)若AB=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
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【推荐3】如图,在四棱锥
中,底面
为正方形,侧面
为正三角形,侧面
底面
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/1/d492d0a0-a6f1-465d-a04e-32e63937878f.png?resizew=163)
(1)求证:
平面
;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebfcf34539673d516eb9b259951a81ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49cfd630472bc73bd8c2209376dbe9d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83e39d958bce9f7969e0113f308cb632.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a043206e1d0f1fc31e4edcb773746941.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/1/d492d0a0-a6f1-465d-a04e-32e63937878f.png?resizew=163)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca5dd496ee0c1170ef6dcc48266ee444.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49cfd630472bc73bd8c2209376dbe9d1.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47d294d69caac577339f11f477b2047e.png)
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解答题-问答题
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适中
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名校
【推荐1】如图,在四棱锥
中,点
都在以
为直径的圆上,
平面
,M为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/4/371c174f-be1b-4e11-934e-f072e6900821.png?resizew=160)
(1)证明:
平面
;
(2)若
是正三角形,
,求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c82a10b4f0c9323d726804c89dd9548.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5f1897a7e856b42f8cee0f286ad913d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a541b81584a032f571159ea152c85a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/4/371c174f-be1b-4e11-934e-f072e6900821.png?resizew=160)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f9157fce2a8339d281178c7c0bccbe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab2a2834d80ff574e79eae8ca8d4e94f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2414af3e0d759c372dc805110ca87fe8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f239fbcc58fc15535db4b5084c4f7253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
您最近一年使用:0次
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解题方法
【推荐2】已知
是正方体,求平面
的一个法向量.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a211ad5a06b505b8365a62c1946f3cb7.png)
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解答题-证明题
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适中
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解题方法
【推荐1】如图,在棱锥
中,
平面
,
,
,
,
分别是
,
上的点,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/7/f9eb4fe3-bf28-4aa1-a475-ce07e8c6b374.png?resizew=208)
(1)求证:
平面
;
(2)求
,
,
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5164a3cc47e266446d49127e2ef10c37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/662698361c6b3ddaf0c28a3c87be53e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9e22143a3f0cb2de51f382836cc274e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e918b70b02a73685e3c536c7f380e2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1cbe7bfc0b5bfac5611b454e03b20625.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/7/f9eb4fe3-bf28-4aa1-a475-ce07e8c6b374.png?resizew=208)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf60ad9db3411f35704fa88d86bfef5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fa7bbd7831e9ff4f8cffc8889d34f05.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f121eabff3c62c1a196d9ca5f6f83f0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50f218914337edd06e59e75d90b777e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/037b342a682cbd4241855a243da3c016.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/432b602bbaf82a4a40091ecfc8a8ffb0.png)
您最近一年使用:0次
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适中
(0.65)
【推荐2】如图三棱柱
中,
,侧面
是矩形,侧面
是菱形,
,
是棱
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/e366d080-0398-45dd-83c1-1eed6d944913.png?resizew=218)
(1)求证:
平面
;
(2)设
是
的中点,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1295976c3cfbb27cbdc72733a2e021d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac61c24f99a4e466f1e2ea011893866.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb5a97c6b563f00d0a71aef901eb7277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/e366d080-0398-45dd-83c1-1eed6d944913.png?resizew=218)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d25e8fc3dda4f8b45491514b6e22a962.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4eb7e9ad5486cf1c5e506b20c5469e8.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7de7cb1d10dd759c0ebd487e4ca34ac8.png)
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