解题方法
1 . 如图所示的五面体中,
是正方形,
是等腰梯形,且平面
平面
,
为
的中点,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/1/5f7325ef-fea7-4210-9ac9-8317e8901ee3.png?resizew=209)
(1)求证:平面
平面
;
(2)
为线段
的中点,
在线段
上,记
,
是线段
上的动点. 当
为何值时,三棱锥
的体积为定值?证明此时二面角
为定值,并求出其余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85a2e10a5aebe40a9018d5ee3ade7af8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5747d138808e8ae03858c07dca6f19f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9003d21719232f65698743d8ecf8edd6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/1/5f7325ef-fea7-4210-9ac9-8317e8901ee3.png?resizew=209)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10e92d42e94cb01dabba1db6fc18c66b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff7e524de0f5d99fbd82f58d28dd4219.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7f6f93171329d508d491143b9d71f7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f1d42d8642fcdd53522c07fe7b3db8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08cc391036004bfc202e934285ee7fa7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f63884ba9b24c3729315d0bb8a230d66.png)
您最近一年使用:0次
解题方法
2 . 在如图所示的六面体中,四边形ABCD是边长为2的正方形,四边形ABEF是梯形,
,平面
平面ABEF,BE=2AF=2,EF
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/1/7bdd7d5b-cfe5-4383-a128-6a9558fd4a51.png?resizew=147)
(1)在图中作出平面ABCD与平面DEF的交线,并写出作图步骤,但不要求证明;
(2)求证:
平面DEF;
(3)求平面ABEF与平面ECD所成锐二面角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd3e927b7b2383ccded03838ae8b30b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cf9a6db3571fa57bfa2d5e4d44c51b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7ffe8515ff6183c1c7775dc6f94bdb8.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/1/7bdd7d5b-cfe5-4383-a128-6a9558fd4a51.png?resizew=147)
(1)在图中作出平面ABCD与平面DEF的交线,并写出作图步骤,但不要求证明;
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8197bf06d017950c85c3ba6a291c095e.png)
(3)求平面ABEF与平面ECD所成锐二面角的余弦值.
您最近一年使用:0次
11-12高三·福建泉州·期末
名校
3 . 已知椭圆
的方程为:
,其焦点在
轴上,离心率
.
(1)求该椭圆的标准方程;
(2)设动点
满足
,其中M,N是椭圆
上的点,直线OM与ON的斜率之积为
,求证:
为定值.
(3)在(2)的条件下,问:是否存在两个定点
,使得
为定值?
若存在,给出证明;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f430e1cde8d059b17a52bd2b45b807c.png)
![](https://img.xkw.com/dksih/QBM/2012/3/4/1570787035594752/1570787041181696/STEM/de477cad4de3405eaba0ae43368ca0df.png?resizew=13)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/075ba8c6fb5ef7288cd3fed425c8e69e.png)
(1)求该椭圆的标准方程;
(2)设动点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7775aa57ca0e62216f3039ed88dceed0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4122ddc651f14b0dbf141793188c1e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3389f53711264b0acba3ba6019f8b908.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbcf846a8da43077ff42ff67ea71aad4.png)
(3)在(2)的条件下,问:是否存在两个定点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3979f27823cdcba516dfa885d8afe19d.png)
若存在,给出证明;若不存在,请说明理由.
您最近一年使用:0次
2010·上海·二模
4 . 本题共有3个小题,第1小题满分4分,第2小题满分6分,第3小题满分6分.
已知椭圆
:
(
),其焦距为
,若
(
),则称椭圆
为“黄金椭圆”.
(1)求证:在黄金椭圆
:
(
)中,
、
、
成等比数列.
(2)黄金椭圆
:
(
)的右焦点为
,
为椭圆
上的
任意一点.是否存在过点
、
的直线
,使
与
轴的交点
满足
?若存在,求直线
的斜率
;若不存在,请说明理由.
(3)在黄金椭圆中有真命题:已知黄金椭圆
:
(
)的左、右
焦点分别是
、
,以
、
、
、
为顶点的菱形
的内切圆过焦点
、
.
试写出“黄金双曲线”的定义;对于上述命题,在黄金双曲线中写出相关的真命题,并加以证明.
已知椭圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d7aea48c44781a844b5c19191f70f61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9374d3462754e846cbb0f7dd5fd28277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8dcc91c2ffb5571eaf944c34f5e8ffe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a9e8d0a22780adc0f72b6063bf6b1ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/309cbe2a7ad325660836eba2da5269dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(1)求证:在黄金椭圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d7aea48c44781a844b5c19191f70f61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9374d3462754e846cbb0f7dd5fd28277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
(2)黄金椭圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d7aea48c44781a844b5c19191f70f61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9374d3462754e846cbb0f7dd5fd28277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ace7c9e3da8613175ca07c54c116127a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
任意一点.是否存在过点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3fb78c5f885034612c0e030b920143d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f27017b6c7cf39eb019210519f5c531.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
(3)在黄金椭圆中有真命题:已知黄金椭圆
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d7aea48c44781a844b5c19191f70f61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9374d3462754e846cbb0f7dd5fd28277.png)
焦点分别是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e23e9dc518bf597c75fc263a3a336f00.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ace7c9e3da8613175ca07c54c116127a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d21500aaf569184db7b098047a88ea01.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48d04015890783f6b8b0264b1d1c9127.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8f30252ca69f981c8f113bd38b502a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ddc11553aa9dd9c19318921b21bb140.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/945e93c9f3515ded840de09a9ba81ce8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5076289823db419f94e9c0c8f4aafd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3fb78c5f885034612c0e030b920143d.png)
试写出“黄金双曲线”的定义;对于上述命题,在黄金双曲线中写出相关的真命题,并加以证明.
您最近一年使用:0次
名校
5 . 已知在正三棱柱
中,
,
.
,
分别为棱
,
的中点,求证:
平面
;
(2)求直线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad1a56baf43ffdf67bc8460856e31fec.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/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57f9d682e5d3cc8573574d8d11636758.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b94e97d085cea077cb82a0b7d2f523e.png)
(2)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e26d9636ad77369535852c6e4493446a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b94e97d085cea077cb82a0b7d2f523e.png)
您最近一年使用:0次
2024-06-01更新
|
795次组卷
|
2卷引用:2024届福建省厦门第一中学高考模拟(最后一卷)数学试题
名校
解题方法
6 . 如图,在四棱锥
中,底面ABCD为平行四边形,
为等边三角形,
,
,
,
.
;
(2)若
,
①判断直线
与直线
的位置关系,并说明理由;
②求平面
与平面
的夹角.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80c753cb1eb73fd8d136d00462970797.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f14b86b8bf99386fc939c9c12b1355ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d152a8b0a10e18aeb42252c9563f47f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34a2989b09435d633d1eee54ed9b591f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae0d25ba47ac8c9f111543460b8031de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6ad7c46b97fbb2c7934636f6f1dc244.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/106763481f13fbc37747abaf0d0f4594.png)
①判断直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
②求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c09afc70f448545336304333d5b5658b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7495688c046142f688c822209c0e968e.png)
您最近一年使用:0次
2024-05-17更新
|
413次组卷
|
2卷引用:福建省厦门市2024届高中毕业班第二次质量检查基础巩固练习数学试题
名校
7 . 如图,在直三棱柱
中,
,
,
,
.
时,求证:
平面
;
(2)设二面角
的大小为
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f121eabff3c62c1a196d9ca5f6f83f0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42da806a6bd2472459f6c4ad1dab7b29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b360c98bd3fd209525fd8fece4246590.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac1c3ea872a20fdc1843cb5ffce8a554.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44b190c8d3d7d7d0e6e959e8a52eae90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea848cd2aa3a464618020475097949fc.png)
(2)设二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/306681bd5aaa51e9c63ab3002e23dec5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aefd06c239145a2b6ae87a955aa51414.png)
您最近一年使用:0次
7日内更新
|
170次组卷
|
3卷引用:福建省漳州市龙文区2024届高三6月模拟预测数学试题
名校
解题方法
8 . 在矩形
中,
,
为边
上的中点.将
沿
翻折,使得点
到点
的位置,且满足平面
平面
,连接
,
,
.
平面
.
(2)在线段
上是否存在点
,使得二面角
的余弦值为
?若存在,求出
点位置;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a7f89fd7ddc3277cf27230a12d60f11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a26a7784c7419d8359fb119c8ecc03d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fa7bbd7831e9ff4f8cffc8889d34f05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fc56c77464a17a1e97b568762a3e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a26a7784c7419d8359fb119c8ecc03d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9068f29d671d76d1e95ba3a4eaff5b96.png)
(2)在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a595401d3a63911df54858576fb17bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dee14db57f0c762aad845cf5b4a243c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
您最近一年使用:0次
2024-05-31更新
|
744次组卷
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2卷引用:福建省漳州市第三中学2024届高三下学期高考全真模拟考试数学试题
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解题方法
9 . 如图,平行六面体
中,侧面
为矩形,底面
是边长为2的菱形,且
为线段
上一点,满足
.
平面
;
(2)若
,求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9b7b7793d29d66dfdd89e7a6564a35c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b4529d1e2f525904d40b33c5946ced2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c32a9ec3b034a8e246e20cbd18cd7e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4aa9084b8fe0fe05c4388d1f835587b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63e4d19bf237a6fca67e0d01a9ddb726.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a65bf87f74420270138ed73a2d38ca48.png)
您最近一年使用:0次
2024-05-14更新
|
201次组卷
|
2卷引用:福建省泉州市永春第一中学2024届高三最后一卷数学试卷
10 . 如图,多面体
中,
和
均为等边三角形,平面
平面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb0b4b072ebf21f947fddc1b70554ceb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c90282d4a37c9a20620d4bbb0c263cae.png)
;
(2)求平面ABD与平面PBC夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea1e3a43d0fa18f6c0888ba804d5b329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acee03d4bb4667b6c345221b6c9b0fa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73636989e83905f8800a865c2b608c43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf6dc837ae85207789b94d109c5c2eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb0b4b072ebf21f947fddc1b70554ceb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c90282d4a37c9a20620d4bbb0c263cae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb5d56d8170b764b80a672cd6c861921.png)
(2)求平面ABD与平面PBC夹角的余弦值.
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