解题方法
1 . 如图是一个半圆柱,
分别是上、下底面圆的直径,
为
的中点,且
是半圆
上任一点(不与
重合).
平面
,并在图中画出平面
与平面
的交线(不用证明);
(2)若点
满足
,求平面
与平面
夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/217ef4133057ffd2a3b1a2da7c59045a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eadd8b2668c34be82fc42346382380a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16d65cecaf8a3dc2953f4109c75a981e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20ebaa32f4f1f4f807ca9aeb7fb29951.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49af9bef16bb8575c46d9a3658e1b016.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1077520a4816bbb5a37fc45359e34c5c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/823f4e614dd9290178c2b9c9fd2460a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1077520a4816bbb5a37fc45359e34c5c.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f08971c21f32470f773ef57614ae0131.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/823f4e614dd9290178c2b9c9fd2460a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/678b28fddb166d90878d24d6e5481080.png)
您最近一年使用:0次
名校
解题方法
2 . 如图,在圆台
中,
为轴截面,
为下底面圆周上一点,
为下底面圆
内一点,
垂直下底面圆
于点
.
平面
;
(2)若
为等边三角形,求平面
和平面
的交线
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae0a4f38420bb9215dbc9c875b755838.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9b7b7793d29d66dfdd89e7a6564a35c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e64beb125bd45dde1a2b17cdd74001ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce1b066f8869d0ff4513f7a99745125.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6d0f9440606475f093d453bfa4d08e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df1e2381971c4dbd3d53dea8ce33e086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8035fc825a001d7d9a3dacd8271662.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbd1c4e883518a7ac5a7517615e47e86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8035fc825a001d7d9a3dacd8271662.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1eddaf3f33bd9a99162c061c9dd99aee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e61dc0fec2de4694075281e882d3c5ac.png)
您最近一年使用:0次
2024-05-01更新
|
893次组卷
|
3卷引用:陕西省安康市高新中学、安康中学高新分校2023-2024学年高三阶段性测试(八)理科数学试题
名校
解题方法
3 . 上海世博会中国国家馆以城市发展中的中华智慧为主题,表现出了“东方之冠,鼎盛中华,天下粮仓,富庶百姓”的中国文化精神与气质.如图,现有一个与中国国家馆结构类似的六面体
,设矩形
和
的中心分别为
和
,若
平面
,
,
,
,
,
,
,
,
,
,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f919bd3dde10dbbc076f7ec5149699.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c4f6f74444b2b7947fc6e35c8d62322.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29989fc4551b8d5cc0328dcef28fffc8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c3ba703df54153b75c79c46d92df1c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc34db5860990e51ba31edc8cdd077c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dde9cb64ad52176fdef71b7446207b85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d5f7dcfc047e963288f442298d2aaca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d021ea5a5760029c6eeb93bae9ed42b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/590dd3b109776fa5521dfc9eecdfb87b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1433137fef4e88aa38f2503cec900358.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b00194912b2521c3fe54d3b0af7563e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/924041c1d6b9970fb6606bd171afb424.png)
A.这个六面体是棱台 |
B.该六面体的外接球体积是![]() |
C.直线![]() ![]() |
D.二面角![]() ![]() |
您最近一年使用:0次
2023-06-28更新
|
909次组卷
|
6卷引用:陕西省西安市阎良区2022-2023学年高一下学期期末数学试题
陕西省西安市阎良区2022-2023学年高一下学期期末数学试题湖北省十堰市2022-2023学年高一下学期期末数学试题江西省龙南中学2022-2023学年高一下学期6月期末考试数学试题福建省永春第一中学2022-2023学年高一下学期期末考试数学试题(已下线)第六章 突破立体几何创新问题 专题一 跨学科交汇问题 微点2 跨学科交汇问题(二)【培优版】【人教A版(2019)】专题16立体几何与空间向量(第五部分)-高一下学期名校期末好题汇编
名校
解题方法
4 . 如图,四边形ABCD是圆柱底面的内接四边形,是圆柱的底面直径,
是圆柱的母线,E是AC与BD的交点,
,
.
(1)记圆柱的体积为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4764374bd2fb78e59cd0b283637baeb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c63055a5d6916f99d07fede49120753f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f737b04ce09bc7e1ed86dc9b3c85203b.png)
(2)设点F在线段AP上,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0724089d732523d6f5d0f0fbc6f64984.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5744f53b3376ffbe7a6bc5044c861273.png)
您最近一年使用:0次
2023-02-23更新
|
6969次组卷
|
15卷引用:陕西省宝鸡市千阳县中学2023届高三第十二次模考理科数学试题
陕西省宝鸡市千阳县中学2023届高三第十二次模考理科数学试题2023届安徽省、云南省、吉林省、黑龙江省高三下学期2月适应性测试数学试题2023年安徽省、云南省、吉林省、黑龙江省联考数学试卷评价(已下线)2023年四省联考变试题17-22云南省2023届高三第一次高中毕业生复习统一检测数学试题山西省大同市2023届高三阶段性模拟(2月联考)数学试题(A卷)山西省晋中市平遥县第二中学2022-2023学年高二下学期3月月考数学试题(已下线)专题13空间向量与立体几何(解答题)(已下线)专题08 立体几何(理科)(已下线)上海市华东师范大学第二附属中学2023届高三冲刺模拟4数学试题山西省大同市第一中学校等2校2023届高三一模理科数学试题(已下线)江西省九师联盟2024届高三上学期10月联考数学试题广东省深圳市宝安中学2024届高三上学期12月月考数学试题河南省安阳市第一中学2023-2024学年高二上学期第二次阶段考试数学试题(已下线)第二章 立体几何中的计算 专题一 空间角 微点10 二面角大小的计算综合训练【培优版】
5 . 在空间直角坐标系中,已知向量
,其中
分别是平面
与平面
的法向量.
(1)若
,求
.的值;
(2)若
且
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85423b5c09668d5c838f41677810606c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6af623ef66b94c322ab3d259edb5462b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/727762c06eb504331d69cb33e43979d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b0fffbec1fe851795dfdd448bf0d165.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5986f2991d45fbf3578f08f27d9fd7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3aa3610a990287d3ac756abae406540d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b0fffbec1fe851795dfdd448bf0d165.png)
您最近一年使用:0次
2023-02-13更新
|
344次组卷
|
4卷引用:陕西省榆林市第十中学2023-2024学年高二上学期第一次月考数学试题
陕西省榆林市第十中学2023-2024学年高二上学期第一次月考数学试题山东省济宁市2022-2023学年高二上学期期末数学试题(已下线)2.4.1 空间直线的方向向量和平面法向量(同步练习)-【素养提升—课时练】2022-2023学年高二数学湘教版选择性必修第二册检测(提高篇)(已下线)模块一 专题2 A 空间向量的应用基础卷 期末终极研习室高二人教A版
名校
解题方法
6 . 将棱长为1的正方体
截去三棱锥
后得到的几何体
如图所示,点
在棱
上.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/16/8e7af8b3-96cd-4e20-b0e1-544eb230765f.png?resizew=255)
(1)当
为棱
的中点时,求
到平面
的距离;
(2)当
在棱
上移动时,求直线
与平面
所成的角
的正弦值的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/089c606d4136a2f017072a3487eea64d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4136e63aa029587b870eb2ff24ca43f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/806625a93511075586360d7f9f335f7c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e72b2e1ff83e95df048745322982451.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/16/8e7af8b3-96cd-4e20-b0e1-544eb230765f.png?resizew=255)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce8f887360a533f0a25b0b34fb11f0a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87c0bfeadcf17b2a45896071f07a4a5a.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce8f887360a533f0a25b0b34fb11f0a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e5c62f22d7afc5627fcb86599faa8e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87c0bfeadcf17b2a45896071f07a4a5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
您最近一年使用:0次
2022-10-11更新
|
421次组卷
|
3卷引用:陕西省宝鸡市千阳县中学2023-2024学年高二上学期期中数学试题
名校
7 . 如图1,直角梯形
中,
,
,
,
为
的中点,现将
沿着
折叠,使
,得到如图2所示的几何体,其中
为
的中点,
为
上一点,
与
交于点
,连接
.请用空间向量知识解答下列问题:
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/15/786e3828-c164-4ab2-b188-132893bc5e5f.png?resizew=403)
(1)求证:
∥平面
;
(2)若三棱锥
的体积为
,求平面
与平面
的夹角
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3753faebdc15d2d2e598d5ffc4487a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a11029ca6b4b9e7f777af0280cf163c.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/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63b43490ca09467a4c8cd8cfe91c94e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/321f96c4f808afe67cf565ca74ae0351.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cad4595d5352b2884568a59d8d766a4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/15/786e3828-c164-4ab2-b188-132893bc5e5f.png?resizew=403)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/065f7ff90e26ff382aa7b709955ad1b9.png)
(2)若三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a3ad76c5b79648e73a91065ef847f17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf31876698721a199c7c53c6b320aa86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6734b2bef8750392d3c5c08b5d878505.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9a814b70236a108be5d6e7ff271fe92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
您最近一年使用:0次
2022-12-08更新
|
279次组卷
|
3卷引用:陕西省榆林市神木中学2021-2022学年高二上学期第四次检测理科数学试题
8 . 如图,
分别是圆台上、下底面的直径,且
,点
是下底面圆周上一点,
,圆台的高为
.
![](https://img.xkw.com/dksih/QBM/2022/5/20/2983383443013632/2985729851711488/STEM/6fb38201888646259f7d2b29e435c99c.png?resizew=189)
(1)证明:不存在点
使平面
平面
;
(2)若
,求二面角
的余泫值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5c4cd264c97c1f261229925cc5a6761.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a11029ca6b4b9e7f777af0280cf163c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080ca48cd27d4bf9d9ef084b558fc17a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01961669cd597f61fa48e9853d678bb8.png)
![](https://img.xkw.com/dksih/QBM/2022/5/20/2983383443013632/2985729851711488/STEM/6fb38201888646259f7d2b29e435c99c.png?resizew=189)
(1)证明:不存在点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4a46fbde58e12b1edc038ae9e921722.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e82bb469f9387fed54e45efd28bd0e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f18a490a22cac27417ddc794f00a1941.png)
您最近一年使用:0次
2022-05-23更新
|
1081次组卷
|
5卷引用:陕西师范大学附属中学2023届高三下学期十一模理科数学试题
陕西师范大学附属中学2023届高三下学期十一模理科数学试题湖北省新高考部分校2022届高三下学期5月质量检测数学试题山东省东营市胜利第一中学2022届高三仿真演练试题数学押题卷(已下线)专题08 立体几何解答题常考全归类(精讲精练)-1(已下线)专题19 空间几何解答题(理科)-3
名校
9 . 如图,在直角
中,PO⊥OA,PO=2OA,将
绕边PO旋转到
的位置,使
,得到圆锥的一部分,点C为
的中点.
![](https://img.xkw.com/dksih/QBM/2022/5/10/2976319442501632/2977682015510528/STEM/644581ed-be74-46f0-acb2-acf907d847a6.png?resizew=140)
(1)求证:
;
(2)设直线PC与平面PAB所成的角为
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e534b545e86c02abd2a0dc75d32b407.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e534b545e86c02abd2a0dc75d32b407.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d5dd6306e00de2ae82d6605308792db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20ccc37b189fa2cbc269ca0b233dac37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16d65cecaf8a3dc2953f4109c75a981e.png)
![](https://img.xkw.com/dksih/QBM/2022/5/10/2976319442501632/2977682015510528/STEM/644581ed-be74-46f0-acb2-acf907d847a6.png?resizew=140)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1e4b16c2c6c9bd089da78122e9d2511.png)
(2)设直线PC与平面PAB所成的角为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6581916f5a65edfea257c804efee007e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b04eb2d56139023560725902bb4be978.png)
您最近一年使用:0次
2022-05-12更新
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1695次组卷
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13卷引用:陕西省铜川市耀州中学2022届高三下学期热身冲刺考理科数学试题
陕西省铜川市耀州中学2022届高三下学期热身冲刺考理科数学试题河南省百所名校2022届普通高校招生全国统一考试猜题压轴卷理科数学试题(已下线)2022年全国高考甲卷数学(理)试题变式题9-12题(已下线)2022年全国高考甲卷数学(理)试题变式题9-12题(已下线)2022年高考浙江数学高考真题变式题10-12题(已下线)专题24 立体几何解答题最全归纳总结-1(已下线)2022年全国高考甲卷数学(理)试题变式题17-20题(已下线)2022年高考浙江数学高考真题变式题19-22题(已下线)上海市华东师范大学第二附属中学2023届高三上学期10月月考数学试题上海市洋泾中学2022-2023学年高二上学期期中数学试题四川省泸县第四中学2022-2023学年高三上学期第三学月考试数学(理科)试题(已下线)重难点01 空间角度和距离五种解题方法-【满分全攻略】2022-2023学年高二数学下学期核心考点+重难点讲练与测试(沪教版2020选修一+选修二)(已下线)模块一 专题1 《立体几何》单元检测篇 A基础卷
名校
解题方法
10 . 如图1,在梯形
中,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
于
,且
,将梯形
沿
折叠成如图2所示的几何体,
为
的中点
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/5/03e9c07d-9faf-4152-864b-368f5a6f37a7.png?resizew=383)
(1)证明:
//平面
;
(2)若图1中
,___________,求二面角
的余弦值.
条件①:图1中
;条件②:图2中四棱锥
的体积最大;条件③:图1中
.
从以上三个条件中任选一个,补充在问题(2)中的横线上,并加以解答.如果选择多个条件分别解答,按第一个解答计分.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a9bfa68259d7a331be323b2038d628a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d31a804f1a5c475251c11b163a26ead9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0f0ad2f5858a0d4cec0b204118732ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bedcb5bef64f44b25cfaaedabe00428f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/5/03e9c07d-9faf-4152-864b-368f5a6f37a7.png?resizew=383)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4eb7e9ad5486cf1c5e506b20c5469e8.png)
(2)若图1中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/267ace52b64e1e7dfc5211e033255b7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f253eece04f2d23e3fdc338f694ffd5c.png)
条件①:图1中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d41e71660013619e13a7cd1fb96ee34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5164a3cc47e266446d49127e2ef10c37.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89daf47651671f5be532e4467a72f032.png)
从以上三个条件中任选一个,补充在问题(2)中的横线上,并加以解答.如果选择多个条件分别解答,按第一个解答计分.
您最近一年使用:0次