解题方法
1 . 已知
,求证
.某同学解这道题时,注意到结论中的三个量
,
,
.由已知条件得到
,
,
.进一步发现三者的关系:
.又观察左边式子的结构发现就是两个数的倒数和,从而联想到以前做过的题目“已知
,
,求证
”,类比其解法得到题目的解法:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f60d4d44e161c4c3e151ad73024a8228.png)
,当且仅当
时取等号.所以
.求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/497d269c30eec393e3f0e877ddbe2983.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/323f4e181b418a66cc36d75e0f8da126.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9f2416d1f75a45a314331146550832e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9db8d3facff8f90f28a936fc5b3ab878.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ea712984ea5017140e20bee226fd5af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/481ee0d1e39e92a4732eea90225eb94c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/936553b69099e03189581a42a5c1d8aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6e90787c63ca5b5f1a45e0f6e85aaa1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0c05be59bdd7874fd8e9ee5ba5b17f4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94440d3e4c073f94f2b266ff99d50e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67ca5fd57c2c2fcc3c7a574fdd1467d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86546d8c56d9c72822cc2c834e240ad1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f60d4d44e161c4c3e151ad73024a8228.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55eb4703dc394b53fef7d12030c470d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/914c9d4dc14490413e77f6262d2a7aa9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/323f4e181b418a66cc36d75e0f8da126.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81e743594b98ac2006344494dddfb345.png)
您最近一年使用:0次
名校
解题方法
2 . 设为数列
的前
项和.已知
.
(1)证明:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dbe110635863de83f12009fc1d76d408.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37336243f9c18724444e1b67727917f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5da72309d2507e2f5e5ed88d8cc08963.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
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2023-09-10更新
|
1609次组卷
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8卷引用:河北省新乐市第一中学2024届高三上学期第一次月考数学试题
3 . 已知数列
满足
.
(1)求证:数列
为等比数列;
(2)设
,求数列
的前n项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaeede12a90aa0cca8b7cd3b9b4273a4.png)
(1)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a080c94bf1ffea8d5af10f9688978fb5.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b106d3c1113b9217724bf99d90de3b9c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b5fd083560d5f57d3f55e6403397926.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
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名校
解题方法
4 . 设
为数列
的前
项和,
.
(1)求数列
的通项公式;
(2)设
,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb4487d7daca378b322a42a8d04f341b.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f3f770c2751f5f81c9b4419e4e99d1f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a051cd30dd080d1a1a22b46b6444ae9.png)
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2023-12-29更新
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8卷引用:河北省金科大联考2024届高三上学期12月月考数学试题
河北省金科大联考2024届高三上学期12月月考数学试题河北省衡水市枣强中学2024届高三上学期期末考试数学试题河北省衡水市深州中学2024届高三上学期期末考试数学试题福建省百校联考2024届高三上学期12月月考数学试题山东省德州市第一中学2024届高三上学期期末数学试题(已下线)考点12 数列中的不等关系 2024届高考数学考点总动员江西省宜春市宜丰中学2024届高三上学期期末数学试题(已下线)重难点5-2 数列前n项和的求法(8题型+满分技巧+限时检测)
名校
解题方法
5 .
为数列
的前
项和.已知
,
.
(1)证明
是等比数列,并求数列
的通项公式;
(2)数列
满足
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/612ca02f7ca42d8cbf9d8336d9f2300c.png)
(1)证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4d4ed61d770a4e82f3aaa6ce9c13903.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50d6d518a78caad6a22173681996795e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
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2023-12-25更新
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7卷引用:河北省石家庄市第二中学2023-2024学年高二上学期期末第一次模拟考数学试题
河北省石家庄市第二中学2023-2024学年高二上学期期末第一次模拟考数学试题陕西省西安市西北工业大学附属中学2023-2024学年高二上学期期中质量检测数学试题四川省宜宾市兴文第二中学校2023-2024学年高二上学期期末数学试题宁夏回族自治区银川市贺兰县第一中学2023-2024学年高二上学期期末复习数学试题(四)(已下线)第四章 数列章末综合达标卷-2023-2024学年新高二数学同步精讲精练宝典(人教A版2019选修第二、三册)青海省西宁市海湖中学2023-2024学年高二下学期开学考试数学试卷(已下线)2024届新高考数学原创卷6
名校
6 . 在
中,角
,
,
所对的边分别为
,
,
,
.
(1)求证:
;
(2)若
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.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)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c4497635b33adc89d4669439236abbe.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c1871203419c14bbe078f220b302343.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97757fd876c0ea02758e3beceb64a5f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b32f2d4d1d2c16c54b2caef17840bfcb.png)
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解题方法
7 . 在数列
中,
,
,
且
.
(1)设
,证明:
是等比数列;
(2)设
为数列
的前
项和,是否存在互不相等的正整数
满足
,且
,
,
成等比数列?若存在,求出所有满足要求的
的值;若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ecf69901899bba130968c7a091790d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ab965b63c10ec92f8235f0faa5919b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0704f453b2de48d36911f7db496bbf82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e97769855336d73371930df1f187875e.png)
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fdb50cacd8eb999c9398a3ec378b416.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eaac721898793d14a799c79db3658685.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc198dee35459651ae1cc73b01be08cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11de7912c83c0eca21eb84e126050b0d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/66acc93c1a14651caf3e39d20ff83bf0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/938c5894c71c8f4d08674250429d88ff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eaac721898793d14a799c79db3658685.png)
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2023-03-30更新
|
537次组卷
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4卷引用:河北省沧州市部分学校2022-2023学年高二下学期3月月考数学试题
8 . 已知数列
的前
项和为
,且
,
.
(1)求数列
的通项公式;
(2)若
,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.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/d1bae03ee4ac75dacfb026290e4207dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ecea472c965f1cab3c1f23139fde63f.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7090e82d18c44a8e5e8c3a0b1a57a6e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e0d4dd03db6b84e8a462de904192222.png)
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2023-03-18更新
|
1038次组卷
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3卷引用:河北省保定市部分学校2022-2023学年高二下学期3月联考数学试题
河北省保定市部分学校2022-2023学年高二下学期3月联考数学试题福建省莆田市2023届高三毕业班第四次教学质量检测数学试题(已下线)安徽省“江南十校”2023届高三下学期3月一模数学试题变式题17-22
名校
解题方法
9 . 已知函数
是定义在
上的奇函数.
(1)求
的值,并判断函数
的单调性(给出判断即可,不需要证明);
(2)若对于任意
,
,且
,都有
恒成立,求实数
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53fc840eacc50ec7d8d2252d223d7ee0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a43b2faa4f81f32d94612dce724e772b.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
(2)若对于任意
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08115d6d9f876dea921a4d32260ff1fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/061813f1ec633c5c4c393c4de7938322.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/131ac7eb1e911c9a40e84235bf3742ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c453c9e122377a0cb03ac92e383e8ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
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2024-01-26更新
|
376次组卷
|
3卷引用:河北省沧州市泊头市第一中学2023-2024学年高一上学期1月月考数学试题
名校
解题方法
10 . 已知数列
的前
项和为
,且满足
.
(1)证明:数列
是等比数列;
(2)求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.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/8b198d3014467bf397a4f4ba489251b3.png)
(1)证明:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0496f142d8ae5acb06e83526eaa3ef87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
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