1 . 已知数列
的前
项和为
,且满足
.
(1)求证:数列
为等比数列;
(2)已知
,求数列
的前
项和.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0df387df5d97ffab16c92b6f6c0f7728.png)
(1)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/82f8b6edfb7d680d88ed991d5c552c43.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1e8a0503abebc7b0f2a60b2ec15d282.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f329b217e1051b23f0d61023cdc6e69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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2 . “阳马”是我国古代数学名著《九章算术》中《商功》章节研究的一种几何体,即其底面为矩形,一条侧棱垂直于底面的四棱锥.如图,四边形
是边长为3的正方形,
,
.
是一个“阳马”;
(2)已知点
在线段
上,且
,若二面角
的余弦值为
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91d5a57d368261e7a0a61d8386459eea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8cee96ca90f9f26644860329443ed56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/faeb97acf19bd3b2c6c77c2814df4d2f.png)
(2)已知点
![](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/69e27dea946df6947fb791374c992dcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6f351b3ffc75878acdbbe4d4926524f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5930602f8d9bb301d34db872d7a3cd53.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
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3 . 已知函数
,则不等式
的解集为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef88bf752cda4bb15e3205d4feccff89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9652e30dad4d1ea51c10b229a10252d.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
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4 . 已知函数
,则下列结论中错误的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7444b2a67506a0b3bef129b6fc5a04f5.png)
A.![]() |
B.![]() |
C.![]() |
D.曲线![]() ![]() ![]() |
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5 . 已知函数![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d5120dd7169a352a82ac137b26b4c28.png)
(1)讨论
的单调性;
(2)当
时,函数
与函数
有相同的最大值,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d5120dd7169a352a82ac137b26b4c28.png)
(1)讨论
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94440d3e4c073f94f2b266ff99d50e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f67b05c1e553c4f11bd50365e024533.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
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解题方法
6 . “肝胆两相照,然诺安能忘.”(《承左虞燕京惠诗却寄却寄》,明•朱察卿)若
两点关于点
成中心对称,则称
为一对“然诺点”,同时把
和
视为同一对“然诺点”.已知
的图象上有两对“然诺点”,则
等于( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ae1567d8f98fabc1a3948f8602cc5e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1eba820e33b03065f2d546e9aea0b7e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2d42553fc43119c1748b8708564fd9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2d42553fc43119c1748b8708564fd9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc72003af058dfdd6ba5ab4827afdef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5395c0276d6a0875f908ea14b689cb4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
A.2 | B.3 | C.4 | D.5 |
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解题方法
7 . 很多人都爱好短视频,为了调查手机用户每天刷短视频的时间,某通讯公司在一广场随机采访男性、女性用户各50名,将男性、女性平均每天刷短视频的时间(单位:h)分成5组:
,
,
,
,
分别加以统计,得到如图所示的频率分布直方图.
(1)若每天刷短视频超过
的用户称为“短视频控”,否则称为“非短视频控”,完成如下列联表,判断是否有
的把握认为是否是“短视频控”与性别有关.
参考数据:
(2)从女性50人中按分层抽样抽出5人,再从5人中随机抽出2人进行进一步交流,被抽到的2人中,既有“短视频控”,又有“非短视频控”的概率.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b7f4f6dcf82909a020c1b8ddfd8bc83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b83a398ed06484652d88e8a0829eab79.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8d40d44bcc2610782af31da21296ec4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9fb81d8b5f8f2223d4b7620c8f9ee2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68feae4c38b4ba68f1e80bf0a22a83b9.png)
(1)若每天刷短视频超过
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c63f6b1652d3e830ed2dbc65253d043.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3866b3757d05ceb0d14427142fb52e9d.png)
短视频控 | 非短视频控 | 总计 | |
男性 | |||
女性 | |||
总计 |
0.10 | 0.05 | 0.025 | 0.010 | 0.005 | 0.001 | |
2.706 | 3.841 | 5.024 | 6.635 | 7.879 | 10.828 |
(2)从女性50人中按分层抽样抽出5人,再从5人中随机抽出2人进行进一步交流,被抽到的2人中,既有“短视频控”,又有“非短视频控”的概率.
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8 . 请在①
,②
,
③
三个条件中选择一个,补充在下面的问题中,
所对的边分别是
,已知_____.
(1)求角
;
(2)若
,点
在边
上,
为
的平分线,求边长
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c55c2d6765572a01f646a8fcf1b660ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28b6e8a8f6a82b3d5510066a0eae566b.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0867d4b6c3d1cc771e5e83974ca111ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab609a6574633ebabcff3e73fa862081.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
(1)求角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3320a13248a3a1208ff6ee85c9d26f36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fabb884dc5f9609de491245463bbe9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
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解题方法
9 . 已知
.
(1)若
,解不等式
;
(2)当
(
)时,
的最小值为3,若正数
、
满足
,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ea5de196c8ac3eaf27d376164718f41.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b108ab31cc093f03cf48ad65429889e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1b4d04800acca6ef5a8696befee0ece.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31f31c8a4f1cab92254d60217b85013a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fff6e7e2b9f2b68b1647f6350b98dc8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/404a00bf430f0f1a0fadc3130b79cb23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7665f6fc755673a94df20bb66c694013.png)
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10 . 若函数
,且
,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ef7d79d7b83e5ac5277a63b9e12894d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a79d3b6033876287443c319ae381dd57.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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