1 . 如图,
是底面边长为1的正三棱锥,
分别为棱
上的点,截面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
底面
,且棱台
与棱锥
的棱长和相等.(棱长和是指多面体中所有棱的长度之和)
为正四面体;
(2)若
,求二面角
的大小;
(3)设棱台
的体积为
,是否存在体积为
且各棱长均相等的直四棱柱,使得它与棱台
有相同的棱长和? 若存在,请具体构造出这样的一个直四棱柱,并给出证明;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/927456b0989846a2f1573844bbaa2105.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19bb1063e139610045f3bca5ca0b2766.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/134ef0b1a2669a09f05bd4dc2496f706.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8783bc74553bf44b61d999a0e4144bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7fcbd32d874c0095b0c993efdc1e7c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab6d47edbcc2ae6efcfd7f28e401e3e9.png)
(3)设棱台
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8783bc74553bf44b61d999a0e4144bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be54e84508decfcce6d2fcbe6c8c1a92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be54e84508decfcce6d2fcbe6c8c1a92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8783bc74553bf44b61d999a0e4144bb.png)
您最近一年使用:0次
2022-11-17更新
|
135次组卷
|
15卷引用:上海市金山区2021-2022学年高二上学期期末数学试题
上海市金山区2021-2022学年高二上学期期末数学试题上海市嘉定区第二中学2021-2022学年高一下学期期末自查数学试题(已下线)专题15 立体几何(练习)-2上海市徐汇中学2022-2023学年高二上学期期中数学试题(已下线)阶段测试(沪教版2020必修三全部内容)-2022-2023学年高二数学考试满分全攻略(沪教版2020必修三)(已下线)11.3 多面体与旋转体(作业)(夯实基础+能力提升)-【教材配套课件+作业】2022-2023学年高二数学精品教学课件(沪教版2020必修第三册)(已下线)11.2锥体(作业)(夯实基础+能力提升)-【教材配套课件+作业】2022-2023学年高二数学精品教学课件(沪教版2020必修第三册)(已下线)安徽省安庆市2023-2024学年高二上学期期末考试数学试题上海市奉贤区奉城高级中学2021-2022学年高二上学期12月月考数学试题第11章 简单几何体(B卷·能力提升练)-【单元测试】2022-2023学年高二数学分层训练AB卷(沪教版2020必修第三册)2004年普通高等学校招生考试数学(文)试题(上海卷)2004年普通高等学校招生考试数学(理)试题(上海卷)上海市金山区上海师范大学第二附属中学2023-2024学年高二上学期期中数学试题上海市宝山区上海师大附属罗店中学2023-2024学年高二上学期第二次诊断调研数学试题(已下线)第五章 破解立体几何开放探究问题 专题二 立体几何开放题的解法 微点1 立体几何开放题的解法(一)【培优版】
2 . 用反证法证明命题:“已知
,求证
,
,
中至少有一个大于30”时,要做的假设是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/051cbc93fb80a37d5edee35e928226a1.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)
A.![]() ![]() ![]() ![]() | B.![]() ![]() ![]() ![]() |
C.![]() ![]() ![]() ![]() | D.![]() ![]() ![]() ![]() |
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名校
解题方法
3 . 如图,四边形
为矩形,且
,
,
平面
,
,
为
的中点.
![](https://img.xkw.com/dksih/QBM/2022/7/22/3027928911282176/3030210845450240/STEM/3315c85be91b4a41b26dad8314c5f1de.png?resizew=179)
(1)求证:
;
(2)若点
为
上的中点,证明
平面
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced06b71073e1bb777f326f06016ce17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcc532cfe64300cb3da9e04a307c957a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/2022/7/22/3027928911282176/3030210845450240/STEM/3315c85be91b4a41b26dad8314c5f1de.png?resizew=179)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/248ddfad39864ab0e183e01f82859e72.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd33764ff4efddfe11a98a609753715c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b8badfeb9e7556486e02ab60df4dd32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80f747eb5b2d21c9de962cbfd4ec4bb7.png)
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名校
解题方法
4 . 如图,在四棱锥
中,底面
是正方形,过
的平面与侧棱
的交点分别是
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/4/6fae32b1-d807-431b-8449-457a3eef0a4b.png?resizew=163)
(1)证明:
;
(2)若
底面
,求证:
平面
.
![](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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adc72cba412508818056817a70552176.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad056c25c0fdcbcc765eb5cbc6093f2b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/4/6fae32b1-d807-431b-8449-457a3eef0a4b.png?resizew=163)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee73452ee4d5437f1399f1235b95e55f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e56fdf217165748fafe938b64fa08179.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f571a1aac46c6d0cf440c0ec2846bf9.png)
您最近一年使用:0次
2022-11-02更新
|
690次组卷
|
3卷引用:四川省大英中学2022-2023学年高二上学期期末考试数学(理)试题
解题方法
5 . 求证:夹在两个平行平面间的平行线段相等.画图,并用图中字母写出已知、求证;写出证明过程.
您最近一年使用:0次
2022-07-05更新
|
95次组卷
|
2卷引用:河南省许昌市2021-2022学年高一下学期期末数学理科试题
解题方法
6 . 在四棱锥
中,底面
为平行四边形,
平面
,
,设平面
与平面
的公共直线为l.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/10/0b73214c-947c-4d7d-90a7-598e26d90aef.png?resizew=202)
(1)写出图中与l平行的直线,并证明;
(2)求证:平面
平面
.
![](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/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f526e2fe627bb4ddebe708c07d0a22fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f59502f452fb6a290484608e65a412df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f526e2fe627bb4ddebe708c07d0a22fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49cfd630472bc73bd8c2209376dbe9d1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/7/10/0b73214c-947c-4d7d-90a7-598e26d90aef.png?resizew=202)
(1)写出图中与l平行的直线,并证明;
(2)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00acc724bbb4569974d4775675a6fda3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af57d63e83ef0e183add10cd6beec65b.png)
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解题方法
7 . 如图,四棱锥P-ABCD的底面ABCD是菱形,PA⊥AB,PA⊥AD,且E、F分别是AC、PB的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/69dda575-4b41-45c5-935a-6aa6fca009ce.png?resizew=160)
(1)证明:EF∥平面PCD;
(2)求证:平面PBD⊥平面PAC.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/14/69dda575-4b41-45c5-935a-6aa6fca009ce.png?resizew=160)
(1)证明:EF∥平面PCD;
(2)求证:平面PBD⊥平面PAC.
您最近一年使用:0次
2022-04-26更新
|
1074次组卷
|
3卷引用:贵州省遵义市第四中学2021-2022学年高二上学期期末质量监测数学试题
8 . 请选择适当的方法证明下列结论:
(1)求证:
;
(2)已知
,求证:
.
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0c1d583e670dac4530bd57ac9118740.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a0c4c098615c6bc7e6dcf72e5b5201a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6e10cc5dd849caccce37fe98a26c598.png)
您最近一年使用:0次
2022-04-02更新
|
510次组卷
|
4卷引用:江西省抚州市七校2021-2022学年高二下学期期末考试数学(理)试题
名校
解题方法
9 . 已知数列
中,
,
(
,
).设
.
(1)求证:数列
是等差数列;
(2)设
,记数列
的前
项和为
.证明,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b13a6e1d671215fc96e4bee3541d1096.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b039543372ce127c7b85782a118f0f12.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0704f453b2de48d36911f7db496bbf82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f093c61867ee4ce75f951d46b9b123.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af18dc260e0c3bd28552a01b3ce03503.png)
(1)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43b7e7cd571c8cd141cbbfe5d0890bf6.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/272563b03d4e5a61b2adc85edc5cbdf0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c88a7ef007c78a93e33bd77c4396626.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c3fec47d2dd2b8099d86c87b6e57de8.png)
您最近一年使用:0次
2022-02-14更新
|
841次组卷
|
4卷引用:北京首师附中2021~2022学年高二上学期1月月考数学试题
北京首师附中2021~2022学年高二上学期1月月考数学试题(已下线)第02讲 等差数列(核心考点讲与练)-2021-2022学年高二数学考试满分全攻略(人教A版2019选修第二册+第三册)(已下线)第四章 数列(A卷·知识通关练) (3)广东省佛山市顺德市李兆基中学2022-2023学年高二下学期3月月考数学试题
解题方法
10 . (1)求函数
的单调区间.
(2)用向量方法证明:已知直线l,a和平面
,
,
,
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9b6a91900d0dfa6296cdee22fdd6fe6.png)
(2)用向量方法证明:已知直线l,a和平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c29f79e8e51e7c35213df9ebe697bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72d2a947e3fdc214d40a7d3f54679a73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c9b2c3117321788078867bd0701743b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ad25ad7785af488a004cae4436019ff.png)
您最近一年使用:0次