如图,四棱锥
的底面是正方形,
平面
,点
是
上的点,且
.
![](https://img.xkw.com/dksih/QBM/2021/10/10/2826527603638272/2826785361362944/STEM/92cbed65311f49f6a2db76e6ae26539e.png?resizew=184)
(1)求证:对任意的
,都有
;
(2)若二面角
的大小为
,求实数
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fb2e071d4e01107dcf7d95cbb86b415.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc02f6ea6cf01a94412c3397ec86552f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/defa5b53043ae802bb1af7d14374406d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37cd8ba5b2a269b6a42aa536edd7fd34.png)
![](https://img.xkw.com/dksih/QBM/2021/10/10/2826527603638272/2826785361362944/STEM/92cbed65311f49f6a2db76e6ae26539e.png?resizew=184)
(1)求证:对任意的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e99146aec0102a510f2357b7013e2d2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/589ddae20626f9aaac616d2a3b5d95bd.png)
(2)若二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02d0f5cb6765dcb8c1d1be85c236c824.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c0927afc571a7c966c98192040979e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
更新时间:2021-10-11 05:32:27
|
相似题推荐
解答题-证明题
|
适中
(0.65)
解题方法
【推荐1】如图,在多面体ABCDEF中,四边形ABCD与ABEF均为直角梯形,
,
,
平面ABEF,
,AD=AB=2BC=2BE=2.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/30/949ff85f-742a-4afd-bfe2-da337373aa2a.png?resizew=151)
(1)已知点G为AF上一点,AG=AD,求证:BG与平面DCE不平行;
(2)已知直线BF与平面DCE所成角的正弦值为
,求点F到平面DCE的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4adf90a8c2b29334cdc5aa5b554991f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d61d846cbc5220533271c962b85c4b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd654221ab95fe241d9e0202443f2609.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eed15d0ed75bf936f224f931da5d950.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/30/949ff85f-742a-4afd-bfe2-da337373aa2a.png?resizew=151)
(1)已知点G为AF上一点,AG=AD,求证:BG与平面DCE不平行;
(2)已知直线BF与平面DCE所成角的正弦值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dee14db57f0c762aad845cf5b4a243c0.png)
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【推荐2】如图所示四棱锥
中,平面
平面
,
,四边形
为等腰梯形,
,
,E为
的中点
(1)求证:
平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
(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/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8254b52b379a420c17d38334940b073.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae1e04eeb4de72e5750dae77bcb6f88a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/639bec6242a4b3f7bfb4b7033a67328c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/16/35aa119f-fdae-42be-869e-12e9fafe80bc.png?resizew=146)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da3dae4417645a025a2897fbe7ab9405.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
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解答题-证明题
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解题方法
【推荐1】如图,
是边长为2的正方形,
平面
,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/65524e33-1c04-4f8b-a886-3a2941c1a287.png?resizew=130)
(Ⅰ)求证:平面
平面
;
(Ⅱ)线段
上是否存在一点
,使二面角
等于45°?若存在,请找出点
的位置;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f4c3f9dd5d0343597a7f58a1989b537.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500df0e782bb081e608f4bc1d576afcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1364213f546b37f8764ddcb59e36ae4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/2/65524e33-1c04-4f8b-a886-3a2941c1a287.png?resizew=130)
(Ⅰ)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cf9a6db3571fa57bfa2d5e4d44c51b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
(Ⅱ)线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f8c7b6766f0581fcd1ecd332afcfae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.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2】如图,已知斜三棱柱
中,
,
在底面ABC上的射影恰为AC的中点D,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/27/ebcfdf7c-4393-43e6-b3d1-b6f18a71bd3b.png?resizew=213)
(1)求证:
;
(2)在直线
上找一点
,使得二面角
的平面角为
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/912c9b5542c5da7a3c5706d5f366b48a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a18722354086c42e62334983fc50eb6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/988ac0247c60cbb622f2330276c6190d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/27/ebcfdf7c-4393-43e6-b3d1-b6f18a71bd3b.png?resizew=213)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f88e7df45acca3fc3d3da3370f0c32bc.png)
(2)在直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53e97fcdcfd6183b976a61ef3222c607.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/260fb70cbd71edc976a8f4274d60043d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2ff7caec4fdd8fb54a3ffbff9692414.png)
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(0.65)
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【推荐3】如图,已知四棱锥
的底面
是菱形,
,
为边
的中点,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/28/29cad0d2-0e71-4784-b1bb-545ca841c52a.png?resizew=184)
(1)证明:
;
(2)试判断线段
上是否存在点
使得二面角
的余弦值为
,若存在求出点
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/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f945a69cf7e8213e50622125cde652f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/077c956ac0eb05cf120e14f17413dfa2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6428c8dffe141f24eb248f728099e09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9791de7c9c09d3c8a0e3c74afa662898.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/28/29cad0d2-0e71-4784-b1bb-545ca841c52a.png?resizew=184)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9bb69be70ba0babb236757648695faca.png)
(2)试判断线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73dad31ce33dc5a58f015280ee7bf450.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/642a7dd471434c923f76809dfa5ee183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
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