23-24高二上·全国·课后作业
解题方法
1 . 已知等差数列
的前n项和为
,且
,
,求
取得最大值时对应的n值.
![](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/ad2da0ff9dc73d62f8162fc3de186150.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7f67e6f9f75fe5e80873eac20abc83b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
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23-24高二上·全国·课后作业
解题方法
2 . 设数列
的前n项和
,求证:
是等差数列.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57c599e7cec6d192fb73218e7882ceca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
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3 . 某体育场一角的看台共有20排,每一排都比前一排多两个座位,第一排有15个座位.问体育场这一角里共有多少个座位?
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23-24高二上·全国·课后作业
4 . 斐波那契数列
满足条件:
,
.按如下步骤将
分解为两个等比数列
,
之和,最后可以得出
的通项公式:
(1)若等比数列
满足条件
,求
的公比q.
(2)若等比数列
,
同时满足条件
,
,且
,求
和
的通项公式.
(3)设
,试写出斐波那契数列
的通项公式.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/644f94297a84a8edbda26f1e408444e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7885a0090b2cab1a7501209f691747c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b69d323ae24f4de27d776747f798a0b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/644f94297a84a8edbda26f1e408444e1.png)
![](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/644f94297a84a8edbda26f1e408444e1.png)
(1)若等比数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/316b5d6779890069e877f081d1833883.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若等比数列
![](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/316b5d6779890069e877f081d1833883.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/288f806f407bee75166d2c43f3c63ea3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36fb00be16d6ca922baa52ae69988c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(3)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/083f9364e291ac5d5f7af1ee93f0a732.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/644f94297a84a8edbda26f1e408444e1.png)
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5 . (中国古代数学问题)
(1)《九章算术》中有如下问题:今有良马与驽马发长安至齐,齐去长安三千里,良马初日行一百九十三里,日增十三里;驽马初日行九十七里,日减半里.良马先至齐,复还迎驽马.问几何日相逢及各行几何?
(1)《九章算术》中有如下问题:今有良马与驽马发长安至齐,齐去长安三千里,良马初日行一百九十三里,日增十三里;驽马初日行九十七里,日减半里.良马先至齐,复还迎驽马.问几何日相逢及各行几何?
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23-24高二上·全国·课后作业
解题方法
6 . 已知等比数列
的前n项和为
,若
,
,
成等差数列,求公比q.
![](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/ebadf2b3ec3dc92cd902eff76085ad46.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20a35d79a1b4df9e4aade6a92f35bea2.png)
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23-24高二上·全国·课后作业
解题方法
7 . 已知等差数列
的前n项和为
,且
,
,求
的前n项和
.
![](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/57f24d2ada5ab0a27cdb322b0f0090b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21d54406efec60657dfbf8666d3ad56e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dea1dd4ffcb4cf0697ca43079f6a1f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
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23-24高二上·全国·课后作业
8 . 已知数列
的通项公式为
.
(1)数列
从第几项起各项的数值逐渐增大?
(2)数列
的哪些项为正数?
(3)数列中是否存在数值与首项相同的项?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa4bf597dac9dfb0d0e9527c24dc4e63.png)
(1)数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(3)数列中是否存在数值与首项相同的项?
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9 . 写出下面数列的一个通项公式:
(1)
,
,
,
,
,…;
(2)1,
,
,
,
,…;
(3)6,66,666,6666,66666,…;
(4)2,0,2,0,2,….
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4b8503f4706b8321e4e79a87eadea84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d59ab85c075a09d55d69e159e4abb268.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/357821e0e5595eaf3028df63d47b2c58.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fe26e5673a3af533756977a52122a72.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57f520104fc54bd1d0e8f44e1c09fffa.png)
(2)1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9db9373e74ecf5d63ad98afe66aa4ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0212732f733e20e61b4ece6d4ed18c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f2f60cdd91ee4a3dfc4da53f9d4c123.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14ca8f182653fdc81b7e09f0bc9efccf.png)
(3)6,66,666,6666,66666,…;
(4)2,0,2,0,2,….
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