1 . 如图所示,在四棱锥
中,底面ABCD为直角梯形,
,
,
,点E为AD的中点,
,
平面ABCD,且
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/20/74591e51-9ddd-42c1-91d5-adcffad16c8e.png?resizew=196)
(1)求证:
;
(2)线段PC上是否存在一点F,使二面角
的余弦值是
?若存在,请找出点F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/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce0d7095ddd69d6ceaf1065b1bc2c79d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56e3296db9e9183be1b4e1eeb3d2eb42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd54724fcdc9c17b35d31c6ba599c93a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b17622ea6f6f5afd1ad817a557e5889d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66c64b1eb9a67b89c3997c91be620f88.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/20/74591e51-9ddd-42c1-91d5-adcffad16c8e.png?resizew=196)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e4125524caac016727c80d2722c5ba3.png)
(2)线段PC上是否存在一点F,使二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21b8c75b0e52a073e9271ed93465b861.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83303d3784492506fc44f2b4d6b07bc1.png)
您最近一年使用:0次
10-11高三上·广东茂名·期中
名校
解题方法
2 . 如图,四面体
中,
、
分别是
、
的中点,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/15/fb30b1be-9b20-46fc-be02-fd044cc27f15.png?resizew=202)
(1)求证:
平面
;
(2)求点
到平面
的距离.
![](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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a65d5853c26657db448af610ac72cca4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6559aabe16c2318687089e7cc498b98.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/15/fb30b1be-9b20-46fc-be02-fd044cc27f15.png?resizew=202)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ce03b310edce42191f9fa75a1c909ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4eb7e9ad5486cf1c5e506b20c5469e8.png)
您最近一年使用:0次
2021-09-10更新
|
531次组卷
|
14卷引用:黑龙江省大庆铁人中学2021-2022学年高三上学期期中考试文科数学试题
黑龙江省大庆铁人中学2021-2022学年高三上学期期中考试文科数学试题(已下线)2011届广东省高州三中高三上学期期中考试数学卷(已下线)2011届江苏省南京金陵中学高三预测卷2数学2014-2015学年黑龙江哈尔滨师大附中高二上学期期末考试理科数学卷山西省朔州市怀仁县第一中学2018-2019学年高二下学期期末数学试题福建省泉州市晋江市南侨中学2019-2020学年高二上学期11月月考数学试题天津市静海县第一中学2017-2018学年高二10月学生学业能力调研数学试题陕西省咸阳市永寿中学2020-2021学年高三上学期开学考试数学(文)试题(已下线)专题19 立体几何综合-2020年高考数学(文)母题题源解密(全国Ⅰ专版)云南省楚雄天人中学2020-2021学年高二3月月考数学(文)试题江西省上高二中2022届高三上学期第二次月考数学(文)试题江西省新余市重点高中2022届高三上学期第二次月考 数学(文)试题吉林省东北师大附中、长春市十一高中、吉林一中、四平一中、松原实验中学2021-2022学年高三上学期联合模拟考试数学(文)试题上海市七宝中学2022届高三冲刺模拟卷二数学试题
名校
3 . 如图,已知四边形
为矩形,四边形
为直角梯形,
,
,
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/17/b255500d-f3c3-46ec-a4ef-a0a10455e4ad.png?resizew=235)
(1)求证:
;
(2)求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/226624e3444853e3cf92d8e11c829a90.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c618b7895122f6006ce248bf41a029a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4151e948feebdf7b91fbe739feafa9bc.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/17/b255500d-f3c3-46ec-a4ef-a0a10455e4ad.png?resizew=235)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c182a9d9fd0a7023b710cd671d9468e7.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13b2ef1b525d302da087241e37387fa6.png)
您最近一年使用:0次
2019-02-14更新
|
852次组卷
|
8卷引用:【全国百强校】黑龙江省大庆铁人中学2018-2019学年高二上学期第一次月考数学(文)试题
【全国百强校】黑龙江省大庆铁人中学2018-2019学年高二上学期第一次月考数学(文)试题安徽省蚌埠市第二中学2019-2020学年高二上学期期中数学(理)试题人教A版(2019) 选择性必修第一册 过关斩将 第一章 空间向量与立体几何 1.4 空间向量的应用 1.4.2 用空间向量研究距离、夹角问题甘肃省天水市第一中学2020-2021学年高二下学期开学考试数学(理)试题(已下线)专题05 用空间向量研究距离、夹角问题 核心素养练习-【新教材精创】2020-2021学年高二数学新教材知识讲学(人教A版选择性必修第一册)(已下线)课时1.4.2 空间向量的应用(02)用空间向量研究距离、夹角问题-2021-2022学年高二数学同步练习和分类专题教案(人教A版2019选择性必修第一册)甘肃省天水市第一中学2020-2021学年高二下学期开学考试数学(理)试题山东省济南市长清区长清第一中学2023-2024学年高二上学期10月月考数学试题
4 . 如图,在四棱锥
中,底面为直角梯形,
,
,
底面ABCD,M、N分别为PC、PB的中点
.
![](https://img.xkw.com/dksih/QBM/2018/10/23/2059733512634368/2060586783703040/STEM/6bea319051654d8b80ebc6fde39731c4.png?resizew=121)
求证:
平面PAD;
求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d02bd5cfe804460846423e77f72db10f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef699f5dc072b853cfe700c6f1abbbae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc9d7d5f80adc68236979bcd89ef4d80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb4564baf209de77802d46cda82995c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/578d3768d0dfd3e19d71307be8a97480.png)
![](https://img.xkw.com/dksih/QBM/2018/10/23/2059733512634368/2060586783703040/STEM/6bea319051654d8b80ebc6fde39731c4.png?resizew=121)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4141b26d2c32655003494a91ad6331b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd19c4db61254be8512edf741bf9f978.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65863c1abad833b79c303bfca24f535c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/508cefb684d9d3f1ddb3180582da5f5c.png)
您最近一年使用:0次
5 . 如图所示,在四棱锥P-ABCD中,PA⊥底面ABCD,AB⊥AD,AC⊥CD,∠ABC=60°,PA=AB=BC,E是PC的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/8/a50c5807-f76f-4264-a768-474742e199c2.png?resizew=164)
(1)求证:AE⊥平面PCD;
(2)求PB和平面PAD所成的角的大小;
(3)求二面角A-PD-C的正弦值.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/8/a50c5807-f76f-4264-a768-474742e199c2.png?resizew=164)
(1)求证:AE⊥平面PCD;
(2)求PB和平面PAD所成的角的大小;
(3)求二面角A-PD-C的正弦值.
您最近一年使用:0次
2019-02-09更新
|
1325次组卷
|
9卷引用:黑龙江省大庆实验中学2019-2020学年高二上学期开学考试数学(理)试题
黑龙江省大庆实验中学2019-2020学年高二上学期开学考试数学(理)试题(已下线)2010年河南省卫辉市高级中学高一第三次月考数学试卷(已下线)2012届山东省莘县实验高中高三一轮复习质量检测理科数学(已下线)2012-2013学年广东省广州六中高一上学期期末考试数学试卷2015-2016学年河南省许昌市三校高一上学期第三次考试数学试卷2015-2016学年甘肃省兰州一中高一上学期期末数学试卷22016-2017学年河北冀州市中学高二上开学测数学理试卷江西省玉山县第一中学2016-2017学年高二下学期第一次考试数学(理)试题(已下线)1.2.4 第2课时 两平面垂直的判定(课后作业)-2018-2019版数学创新设计课堂讲义同步系列(苏教版必修2)
6 . 如图(1),在
中,
,
,
.
,
分别是
,
上的点,且
,
,将
沿
折起到
的位置,使
,如图(2).
![](https://img.xkw.com/dksih/QBM/2018/7/16/1989942535307264/1990977815969792/STEM/5030e989-d721-439a-bbac-caef599054fe.png?resizew=386)
(1)求证:
平面
;
(2)若
是
的中点,求直线
与平面
所成角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7281b641656a5992abaafb4190ca9afc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e3262fc038bbec5e7c8cc47df08bef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f8eeeea1c9652cacce976f8129cf520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1682d306c38087d9e6f7efb9cec596a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95a078495ba47076ccaa28b46f765d80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/377b5f7197e5bd1afeea4d931307956a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aefe4a3e7a7fa195ed6a6712447639b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c03f13bba5fed0f0302c0b726b2041a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdb2fef4031c10abc18c8747af6b9a8a.png)
![](https://img.xkw.com/dksih/QBM/2018/7/16/1989942535307264/1990977815969792/STEM/5030e989-d721-439a-bbac-caef599054fe.png?resizew=386)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d26d8a9d64ad3c8cba28840b41ed7837.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fa7bbd7831e9ff4f8cffc8889d34f05.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10d8eb4a9f462ca0c1d49c3fe91e720d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db54223bb3fc2fe2497213a4d1f94827.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/923189afc198d153c79059a827f63c87.png)
您最近一年使用:0次
2018-07-18更新
|
555次组卷
|
4卷引用:【全国百强校】黑龙江省大庆铁人中学2018-2019学年高二上学期期末考试数学(理)试题
【全国百强校】黑龙江省大庆铁人中学2018-2019学年高二上学期期末考试数学(理)试题黑龙江省大庆铁人中学2018-2019学年高二上学期期末考试数学(理)试题【全国百强校】重庆市第一中学2017-2018学年高二下学期期末考试数学(理)试题(已下线)【新东方】高中数学20210429—001【2020】【高二上】
名校
7 . 如图,在四棱锥
中,底面
为正方形,且
,其中
,
,
分别是
,
,
的中点,动点
在线段
上运动时,下列四个结论:①
;②
;③
面
;④
面
,
其中恒成立的为( )
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/29/62ac9991-6930-44e4-8fb6-41e5af5e66f0.png?resizew=233)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26524ae4755f7156a3c62c0548bc524f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c2bc5e50b8dfa02601c70822252854a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc8ccede05f9270d0f04a9545636790.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d1aba56e04a373cefa813b31a3d99f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3834a4bb20d2b065695dbf53091b065.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5000fea066102e62cf2128ccbbd2b3e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4862958e60c245dc9a5d9cb57d31eb4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cc6f6dfdbe7d39891c35f67e1a95c7f.png)
其中恒成立的为( )
![](https://img.xkw.com/dksih/QBM/editorImg/2022/8/29/62ac9991-6930-44e4-8fb6-41e5af5e66f0.png?resizew=233)
A.①③ | B.③④ | C.①④ | D.②③ |
您最近一年使用:0次
2018-07-16更新
|
1487次组卷
|
7卷引用:【全国百强校】黑龙江省大庆实验中学2017-2018学年高一下学期期末考试数学(理)试题
8 . 如图,在三棱锥
中,
,
,且
,
为线段
的中点,
是线段
上一动点.
(1)求证:
;
(2)当
时,求证
;
(3)当
面积最小时,求点
到面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc2aaed1e9ead175f30f7130569d0411.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc2aaed1e9ead175f30f7130569d0411.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52eee2d0f096d924ed16a035ddf8f5e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6707b8092171fc1902e2d91bc8f1d701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed5034a973110e2a6eb2e7d5699c24f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1a9c6a736e6eac98a676fa3232db5a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4d260c4df7b0dc180af6980d21f3371.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44c324894742cb48dbe75516843601a0.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00d103261f612af48cd98cd5119a83f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a20e5d585fbf903ee5affa6d083ab95f.png)
(3)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7e437375b731a097c117c3816f13772.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93f76b6ac1b8875af7156f3239dae6f7.png)
![](https://img.xkw.com/dksih/QBM/2018/7/16/1989558709649408/1989961491013632/STEM/8f890f20a013404bb07d5e262ffb719a.png?resizew=166)
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9 . 如图,四棱锥
的底面
为菱形,
,
,
分别为
和
的中点.
(
)求证:
平面
.
(
)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/32d0710321d97361e5782124bbf7f0c9.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/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f16835e3f230ba3f543b6804e445e283.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
![](https://img.xkw.com/dksih/QBM/2018/6/25/1974931989143552/1979730087067648/STEM/f5ab7af3de0e443ba7e7bf096fb0a9af.png?resizew=241)
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2018-07-02更新
|
8677次组卷
|
8卷引用:黑龙江省大庆中学2020-2021学年高二10月月考数学试题
黑龙江省大庆中学2020-2021学年高二10月月考数学试题【全国百强校】北京东城北京二中2017-2018学年高二上学期期中考试数学(理)试题江西省赣州市南康区南康中学2019-2020学年高二上学期10月月考数学试题2安徽省芜湖市城南实验中学2019-2020学年高二上学期期中考试数学(文)试卷黑龙江省哈尔滨市第六中学2020-2021学年高三上学期期中考试数学(文)试题陕西省咸阳市武功县普集高中2021-2022学年高一上学期第二次月考数学试题湖北省天门中学、仙桃中学2021-2022学年高一优录班下学期2月联考数学试题四川省峨眉第二中学校2022-2023学年高二上学期期中考试理科数学试题
10 . 在如图所示的几何体中,四边形
是等腰梯形,
,
,
平面
,
,
.
![](https://img.xkw.com/dksih/QBM/2018/6/16/1968590889033728/1971456690012160/STEM/aa1fb9db4e344cbab984b8a9be279d02.png?resizew=185)
(1)求证:
平面
;
(2)求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b37591109b0a0ec5ffe2133f83310eca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea4f5eec0addba78f2e0cdfb7ecc59a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7b5a90e556da12d63b7f481bd8e874c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53c51c25b65a37b676ae3c3b71c29f9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a81de875a8c8fc6f7e70f31e4a2b80cc.png)
![](https://img.xkw.com/dksih/QBM/2018/6/16/1968590889033728/1971456690012160/STEM/aa1fb9db4e344cbab984b8a9be279d02.png?resizew=185)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97a9b32570d553161be04d13954e92a1.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/274cf35acb4a1748d15c39d15a9bea7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4abcf61e035c16b9ea643ee6114bbeb0.png)
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