1 . 如图,在三棱柱
中,
是边长为4的正方形.平面
平面
,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/7/b78f617c-b93f-4d38-bbd1-8a2e6b762970.png?resizew=138)
(1)求证:
;
(2)求二面角
的余弦值;
(3)证明:在线段
存在点D,使得
,并求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac61c24f99a4e466f1e2ea011893866.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3d7090639341730951c1bc3c9b6164e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ac61c24f99a4e466f1e2ea011893866.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d9fb806bf3862d351dc4e4ffa3a2283.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/7/b78f617c-b93f-4d38-bbd1-8a2e6b762970.png?resizew=138)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc0a886f1192d450ced9fd875e78425e.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95183b555d54b3a09ac20e9dcacb02ec.png)
(3)证明:在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c84a436704964dc76f16c2c23665ab3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c04c68f1ef1e37534b5bbc7a1f592ef7.png)
您最近一年使用:0次
名校
解题方法
2 . 如图,在多面体
中,四边形
为直角梯形,
,
,
,
,四边形
为矩形.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/20/d65e1ada-22dd-4985-80ee-4f85890be558.png?resizew=182)
(1)求证:平面
平面
;
(2)线段
上是否存在点
,使得二面角
的大小为
?若存在,确定点
的位置并加以证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c162736b719327a2acd7c4d313e1d93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f79863ffcfa63117ca6741b20a48e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ccd20e6f2c8ac1ead51bdf649f005ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/479bb5e937f4fdb1fcbca229e62e0e80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a301e2a62dc7f46992f6f17d88f87a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/941ae54e27bcb5c3909350049f2afd85.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/20/d65e1ada-22dd-4985-80ee-4f85890be558.png?resizew=182)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bb5012f6c70a1e98d682b6d021fadd8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
(2)线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411461db15ee8086332c531e086c40c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3aa14a5c8a3c0cbd3a0ab5752957ddc2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9303b41310b6bf2a5fe9b66dfcd7fcb5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73465a1f9aa03481295bf6bd3c6903ac.png)
您最近一年使用:0次
2018-02-16更新
|
397次组卷
|
4卷引用:广西壮族自治区防城港市2023届高三下学期4月月考数学(理)试题
广西壮族自治区防城港市2023届高三下学期4月月考数学(理)试题山东省烟台市2017-2018学年高二上学期期末考试数学(理)试题(已下线)《2018届优生-百日闯关系列》数学专题三 第一关 以立体几何中探索性问题为背景的解答题四川省绵阳市绵阳南山中学实验学校2022-2023学年高三下学期4月月考数学理科试题
名校
3 . 在四棱锥
中,
,
,
和
都是边长为2的等边三角形,设
在底面
的射影为
.
![](https://img.xkw.com/dksih/QBM/2017/3/6/1637836815663104/1637860221419520/STEM/9f3f9bef-f847-4992-9bc4-4e514e3a462c.png?resizew=184)
(1)求证:
是
中点;
(2)证明:
;
(3)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db08db31046bf98eb01abfbf356059ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c235aa3c3d273fdf205b1057eea7439.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acee03d4bb4667b6c345221b6c9b0fa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://img.xkw.com/dksih/QBM/2017/3/6/1637836815663104/1637860221419520/STEM/9f3f9bef-f847-4992-9bc4-4e514e3a462c.png?resizew=184)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da48240e7fc3248f773ac1500c15ec14.png)
(3)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b33b7213d99a817bff19bcf740a0697c.png)
您最近一年使用:0次
2017-03-06更新
|
883次组卷
|
5卷引用:2017届广西柳州市、钦州市高三第一次模拟考试数学(理)试卷
解题方法
4 . 已知点
,动点
满足
,记点
的轨迹为曲线
.
(1)求
的方程;
(2)若
是
上不同的两点,且直线
的斜率为5,线段
的中点为
,证明:点
在直线
上.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b10869dee07ab7948bfdb81ad58f134.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1350897d718a2592dfe8f8ddc5154e5c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e7f8878d628d46bcb847f791857b650.png)
您最近一年使用:0次
2024-03-10更新
|
404次组卷
|
2卷引用:广西百所名校2023-2024学年高二下学期入学联合检测数学试题
11-12高二上·浙江台州·期中
名校
5 . 如图,在梯形
中,
,
,
,四边形
为矩形,平面
平面
,
.
平面
;
(2)设点
在线段
上运动,平面
与平面
的夹角为
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1c0ee0aca57a218e5612835ab49ee2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e075468e7fb0bf30229aec01a7205977.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bbc56d42b003cbcb1fbe5c50e55b26b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c0db1f4f666a9be9ede868065a50997.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3362a45b72536c714c5107b0ae94f1c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2ffc6952e988d04f22f0fb2f7f0ab7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bbc56d42b003cbcb1fbe5c50e55b26b.png)
(2)设点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daf2f0df53aa68c9c334165034788166.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2db1674add0f4a1a24f5ed893b1c5d0.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
2024-03-03更新
|
254次组卷
|
35卷引用:广西南宁市第二中学2023-2024学年高三下学期5月月考数学试题
广西南宁市第二中学2023-2024学年高三下学期5月月考数学试题(已下线)2011-2012年浙江省台州中学高二第一学期期中考试理科数学(已下线)2012届河北省衡水中学高三上学期期末考试理科数学(已下线)2012届山东省烟台市高三下学期3月诊断性测试理科数学(已下线)2015届浙江省嘉兴市第一中学高三上学期期中考试理科数学试卷2015届山东省日照市高三12月校际联合检测理科数学试卷2016届山东省日照市一中高三上学期期末考试理科数学试卷2017届湖南长沙长郡中学高三入学考试数学(理)试卷2017届湖北襄阳五中高三上学期开学考数学(理)试卷2017届浙江名校协作体高三上学期联考数学试卷2017届山东寿光现代中学高三实验班10月月考数学(理)试卷江西省南昌市第二中学2016-2017学年高二下学期期中考试数学(理)试题四川省乐山市2017-2018学年高二上学期期末教学质量检测数学理试题【全国校级联考】江西省南昌市八一中学、桑海中学、麻丘高中等八校2017-2018学年高二下学期期中考试数学(理)试题【全国百强校】黑龙江省哈尔滨市第六中学2018届高三下学期考前押题卷(二)数学(理)试题山西大学附属中学2017-2018学年高二3月月考数学(理)试题【全国百强校】福建师范大学附属中学2018-2019学年高二上学期期末考试数学(理)试题【市级联考】江西省宜春市 2019 届高三4月模拟考试数学(理科)试题【全国百强校】湖北省华中师范大学第一附属中学2019届高三月考(六)数学(理科)试题智能测评与辅导[理]-空间几何体的三视图、表面积、体积湖南省永州市道县、东安、江华、蓝山、宁远2019-2020学年高三12月联考数学理试题湖南省五市十校2019-2020学年高三上学期第二次联考数学(理)试题河北省武邑中学2018-2019学年高三下学期期中数学(理)试题湖南师范大学附属中学2018-2019学年高三下学期第六次月考数学(理)试题2020届辽宁省大连市第二十四中学高三4月模拟考试数学(理)试题辽宁省沈阳市东北育才学校2021-2022学年高二上学期第一次月考数学试题黑龙江省哈尔滨市第九中学校2022-2023学年高二10月月考数学试题黑龙江省佳木斯市第十二中学(佳木斯市建三江第一中学)2022-2023学年高二上学期期中数学试题辽宁省葫芦岛市兴城市高级中学2022-2023学年高二上学期期末数学试题吉林省长春市第二中学2023-2024学年高二上学期第一次学程考试数学试题(已下线)第一章 空间向量与立体几何(压轴必刷30题4种题型专项训练)-【满分全攻略】2023-2024学年高二数学同步讲义全优学案(人教A版2019选择性必修第一册)(已下线)专题01 空间向量与立体几何(3)四川省宜宾市叙州区第二中学校2023-2024学年高二上学期期末模拟考试数学试题辽宁新高考联盟(点石联考)2023-2024学年高二下学期3月联合考试数学试题江苏省南京市第五高级中学2023-2024学年高二下学期5月阶段性质量监测数学试卷
名校
6 . 如图,O是圆柱下底面的圆心,该圆柱的轴截面是边长为4的正方形ABCD,P为线段AD上的动点,E,F为下底面上的两点,且
,
,EF交AB于点G.
时,证明:
平面CEF;
(2)当
为等边三角形时,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d38d97f03faed3152db2fd3bd1919944.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e69babe5b1123f5e171c8845cbe4987c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdd03f8f2d904cbb8888188185956784.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbc6f007dbf1c1a36eb031e520608403.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91b51d3992644d37dc71c9b5a97d515c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29f8c417f5c19cc076dc6baeb0c173a9.png)
您最近一年使用:0次
2024-01-25更新
|
134次组卷
|
2卷引用:广西壮族自治区三新学术联盟2023-2024学年高二上学期期末教学质量检测数学试题
解题方法
7 . 如图,在正方体
中,
为平面
的中心.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/13/1ee695fe-0aca-4c2d-8ef3-c50b6aed425f.png?resizew=159)
(1)求证:
平面
;
(2)求点
到平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bafa7168302e524813426a0fa494c86f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/13/1ee695fe-0aca-4c2d-8ef3-c50b6aed425f.png?resizew=159)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34d28074ee5af1441242700388b3a9c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a935b7d21a103a264b6e96ecf82dbe4a.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6795cae2df43a722e1355e9562d93c09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a935b7d21a103a264b6e96ecf82dbe4a.png)
您最近一年使用:0次
解题方法
8 . 如图,正三棱柱
中,E是棱
的中点,
,点F在线段AC上,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/18/2d3e7df9-8e23-43a6-9443-c8e516afff97.png?resizew=125)
(1)求证:
平面
.
(2)求平面
与平面
的夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92105835f8075cb75dff244e908370b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4df433d81860395de40492371b78d93.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/18/2d3e7df9-8e23-43a6-9443-c8e516afff97.png?resizew=125)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1c920d02068d0e63ffdab70786c526d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bff3ccea5989c60e51e321af3f53f54.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bff3ccea5989c60e51e321af3f53f54.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
您最近一年使用:0次
2024-01-18更新
|
337次组卷
|
2卷引用:广西玉林市部分学校2024届高三上学期12月模拟数学试题
名校
9 . 如图(1),在
中,
,
,
,
分别是
,
的中点,将
和
分别沿着
,
翻折,形成三棱锥
,
是
中点,如图(2).
(1)求证:
平面
;
(2)若直线
上存在一点
,使得
与平面
所成角的正弦值为
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd967903ed5a6f640a5b801ec8be0070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f8e9ec412ea0355e4e5cd06c60e5fee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0e7d395bc97771671c5001a52138313.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/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d631f45bc652539853f236952afa5bbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad09a769a75b107390b9eeccc929f761.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e6e490f703eb6c9bb1278c78ebc2d661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/212b200cb65843fe03aab377d53991d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/20/c9c51067-307b-48e7-a4df-d5298c2b636d.png?resizew=189)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a7442b64b37f685bc3ae88ff450c1a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9a32bd7a1b78b5a0ec562c4025aea8c.png)
(2)若直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acc290b44635265137fdf13146b6a6d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf3d566704b44ea4ef1f99c37bd46902.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e6c2dad46a9052a4185a4f7b4ae8a2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/785f4eb0787ffc744fb1018f0c6c347f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db8305c4ffbf876642440c3d28e91e9f.png)
您最近一年使用:0次
2024-02-04更新
|
239次组卷
|
2卷引用:广西柳州市柳州高级中学2023-2024学年高二上学期开学考试数学试卷
10 . 如图,在三棱锥
中,侧棱
底面
,且
,
,过棱
的中点
,作
交
于点
,连接
,
.
(1)证明:
;
(2)若
,三棱锥
的体积是
,求直线
与平面
所成角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccd4fd4b7a4d6b8ca0c5827c055a9ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/587df01a98f499a9f361aafd8c3dac39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615fc8790237a1b09af51d6bcad6b595.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a4a6a1e70241d600bc6c104313eac61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aa2b5e09f8ec785c59900a529390a02.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/4/e75dd94d-92fc-4b7f-a681-7a0a8e1e8a7e.png?resizew=131)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aaef9e92d148afff22761d5e027d3ee.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b80ee363635d73f601654339028daec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b115316e0fcd2ef46a4dd383472996e4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0467b0675c3ecfb282cc88255284d3e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03428a8f91a5674cb8f54766c165f7e.png)
您最近一年使用:0次