1 . 已知递增数列
的前n项和为
,且
,
.
(1)求数列
的通项公式;
(2)设
.
(ⅰ)求数列
的通项公式;
(ⅱ)求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e84c2e4a2a86ffc252955c06e9b567e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/930bc56406e69b785b37a83d48e36724.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e37b430b94a1afdb43f2a80782627c02.png)
(ⅰ)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(ⅱ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f3d151cbe277608d3a6cfbbe3f5eb9a.png)
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名校
2 . 公差大于零的等差数列
中,
,
,
成等比数列,若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/715aaa320d35fd92b2dcd9573ab8b489.png)
_____________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f65fc200f10b97588a0c9896277c9c64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d33ec7236bccfedbe3baefd35e45f1e0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e84c30444f13d37ada78285dc4f83b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1928c254cfada1f75a5cd1e34db5a63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/715aaa320d35fd92b2dcd9573ab8b489.png)
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3 . 已知等差数列
,满足
,
,正项数列
的前
项和为
,且
.
(1)求数列
和
的通项公式;
(2)求![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64c445ae9b9b8e23fbafe3bf32cd58b8.png)
(3)在
,
之间插入1个数
,使
成等差数列,在
,
之间插入2个数
,
,使
成等差数列,
;在
,
之间插入
个数
,使
成等差数列.
①求
;
②求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c83f24b32abf4b2cb15e326063e84a3d.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/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fc5eac09ed870c6711d94e558a25a9b.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64c445ae9b9b8e23fbafe3bf32cd58b8.png)
(3)在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b715e7842b95f654f16056a7c7f2abe9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13423c094861baf4b759b7f3d8c3c226.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a37711dd13e400346369d9d366018de7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47e524013b85f8ecda29773f0fbcaf7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13423c094861baf4b759b7f3d8c3c226.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57483e04fd1840c87ac5325157149877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05ffd1d0d2f8ac94173a589eb526851c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bf922f855f5c6ba4f76ce9c72ab5465.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50503e7c9b6e485253285cdd0c7df30b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37e5531913e2f170465d8df01795cd51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686ece75006ad358f23314dc8a246e11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e95931effbd59c43e8ed1ea09962b84f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c12353dfeb825f6b593d46b94a24af2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/119dc692b6bb23baba1e27a909c4b6b2.png)
①求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cc38dee83ec4bbaed6f62c55e59f4f4.png)
②求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91ee33508bf5c846d5bd5c19d7b6844f.png)
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解题方法
4 . 已知等差数列
的前
项和为
,
,
,数列
是公比大于1的等比数列,且
,
.
(1)求
,
的通项公式;
(2)数列
,
的所有项按照“当
为奇数时,
放在
的前面;当
为偶数时,
放在
的前面”的要求进行“交叉排列”,得到一个新数列
:
,
,
,
,
,
,
,…,求数列
的前7项和
及前
项和
;
(3)是否存在数列
,满足等式
成立,若存在,求出数列
的通项公式,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/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8a0eecb5b800fce9ae10aed86ffee62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee7f18ec0020048985d101969880d93e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f90221b91dabf8a382486cdb4fea5d28.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a738600092c6dbff35a59954f8b0788.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.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/686ece75006ad358f23314dc8a246e11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686ece75006ad358f23314dc8a246e11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b715e7842b95f654f16056a7c7f2abe9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13423c094861baf4b759b7f3d8c3c226.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57483e04fd1840c87ac5325157149877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daf464629fa321a6ff7401ab79f07083.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb1f7ed820a91b5e6fb31606ece9b9db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95184a1a20419163065949815e54f174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85f0818bdac0985b3a823200d552f29f.png)
(3)是否存在数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b783cf91e34e692ce8e171f0965cb53f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ebaf7c9df85e98dd4317b05a890b1c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b783cf91e34e692ce8e171f0965cb53f.png)
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解题方法
5 . 已知数列
为各项不为零的等差数列,
为数列
的前
项和,
,则
的值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](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/7702425507306b9722fd26b35eb1f1cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7da2f386b78cdf6489efaa2f5820d3e.png)
A.4 | B.8 | C.12 | D.16 |
您最近一年使用:0次
6 . 已知数列
是正项等比数列,
是等差数列,且
,
,
.
(1)求数列
和
的通项公式;
(2)设
数列
的前n项和为
,求证:
;
(3)
表示不超过x的最大整数,
;
求(i)
;
(ii)
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ebaf2a2590bb84d646957f913d78f6dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd5f23ec2f95bb3942aa7a5ba34c774b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d7c32c0c4afec905291438500883a00.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f38e377428e6e3f2298542e06c131f70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbc36c446c091c7fa91cec5e26557274.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c4f5908d6a1217e493ed7586b6964dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f4d040e6d47b2f2b22edf0992f5c8cb.png)
求(i)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95f98d47d947a295ee4a4cbe286086d1.png)
(ii)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2250115e8fed417f349122c3d8a36fd.png)
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名校
7 . 在等差数列
中,公差
,若
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/812be9806122241c476ba1db516c4823.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14e20456dd2919275904c49c954d01d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd707b69a11f8de5566f23c1a2a9ff5a.png)
A.12 | B.13 | C.14 | D.15 |
您最近一年使用:0次
名校
解题方法
8 . 数列
是等差数列,其前n项和为
,数列
是等比数列,
,
,
,
,
.
(1)求数列
、
的通项公式;
(2)
的前n项和
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa881a6832e80d914dfd72743491244f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1703c5b9687189ad0d7ece956324cac6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af0dd3fb6af23def773e1b0032a4f3c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c75eb1bce65b48f7ad06aad5b91fd467.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53f5965468f4083a0be2f0547dd8ef31.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2767882820f4ba0defde0e412adb747f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3853475e5d5310e0b325de06c55116c9.png)
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9 . 已知
为等差数列,前n项和为
,
是首项为2的等比数列,且公比大于0,
,
,
.
(1)求
和
的通项公式;
(2)若数列
满足:
,求数列
的前n项和
;
(3)若数列
满足:
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/696d0e6b9013d2e5fdf3feb280c58e18.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ff86be56090d576aad0c0945a6bd2bd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dbaed111f759d66a140168905f2026b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fb0344eb6d3543a6c80803e85f60b26.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9221c0c92a526f65533cdc5400767af.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
(3)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b783cf91e34e692ce8e171f0965cb53f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b0849999199ab6c92a157b0041d652b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de97a62cdcd267dd753ec66f2adc3419.png)
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名校
解题方法
10 . 有n个首项都是1的等差数列,设第m个数列的第k项为
,公差为
,并且
成等差数列.
(1)当
时,求
,
,
以及
;
(2)证明
(
,
,
是m的多项式),并求
的值;
(3)当
,
时,将数列
分组如下:
(每组数的个数构成等差数列),设前
组中所有数之和为
,求数列
的前n项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cda60be3ec6a53c2186021809f87d2ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee8598379ec01edc16c72c1d3fa3ce81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bf101d0cde32b057c21d42a2b336764.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/599d18f02ae5e12191a37cd2d886dc93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/498d357985304a737e7a01272ebbcf15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f4b25db4e5f4a3743476ae088720fb4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/597b1b4a90194fdb88a0a9a3022f5038.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64f2fa5d1e2f6118ea97b390dcfaf293.png)
(2)证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2470082d0a6aa317030c6904f438c41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/615b5e9149cb77ee71a4684bfd43e98a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8be646cd52d7f2f1714e7542e75810f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/adad9633b73dfbbb3d84b4f15979e99e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cca4b2f545d6cfd6764ad19c7bc2c2f8.png)
(3)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dea6578afabc23f5d7041b88c3790dd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf8b33cde65d8456d9a56a19f5c1a377.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/463195d16c135c5aea8fc05fa74a5273.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02dfd2fab2d2a804adcfce8ce36f556f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f53e88f967e1e79b7fd23bc4af4ac862.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cb7b05a076e75ba6ca76e758a590e9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
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