已知公差d不为0的等差数列
的前n项和为
,
,
.
(1)求数列
的通项公式;
(2)若数列
,
,求数列
的前n项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e8c45e4c4ab30665338dd87a2258f23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b4e32575d33b8a9979f4760afd361f9.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95e191086446263b7bbbd93613577c42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d44ddab6e0c60119be69985ae7fa65b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c88a7ef007c78a93e33bd77c4396626.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
更新时间:2022-08-30 10:16:34
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解答题-问答题
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【推荐1】已知数列
的前
项和为
,满足
.数列
满足
,且
.
(1)求数列
和
的通项公式;
(2)是否存在正整数
使
成等差数列,若存在,求出所有满足条件的
;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/f985ba3b26e98eff61d15c39e627fa21.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fb0747f9aeec4b8baf1c00149c5076f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59dd6c97d2ee3e74ba5730f1cbcc1d43.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)是否存在正整数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/280860dd039e1305a5ccc455f63e8223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a0b7489288d49ee8a5c4ba75b63b405.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/280860dd039e1305a5ccc455f63e8223.png)
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解答题-证明题
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【推荐2】用反证法证明:若三个互不相等的正数,
成等差数列,求证:
不可能成等比数列.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88f2599ca8b6b683e57a82699c8b1ebb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88f2599ca8b6b683e57a82699c8b1ebb.png)
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【推荐3】已知数列
,
,
,且
,
是
与
的等差中项.
(1)求数列
的通项公式;
(2)若
,
,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62fdd2881afea79bce25693f1ab72f61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34ff2bf6dd6a240af2434c7e8e5abf85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88b39500ead6dba7eba9a4677d3d9acb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61d473bfcc52ebc119430335531488a3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daf464629fa321a6ff7401ab79f07083.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4498c2062aa890dd722405252da1280f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac96b09d3eccdb9a4c17ecbdec9ecebf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
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解题方法
【推荐1】已知
为各项均为整数的等差数列,
为
的前
项和,若
为
和
的等比中项,
.
(1)求数列
的通项公式;
(2)若
,
为数列
的前
项和,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/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02a2da939bebfc6e6c25c1d67a4fd9ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eca7e7b23fd74e3cf89ac541cb7a5d88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5731f65834e58bb01c8d21a695e395ce.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50a813139b92a24e1124ef96e3e485f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.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)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
名校
解题方法
【推荐2】已知等差数列
的前
项和为
,
,
.
(1)求数列
的通项公式;
(2)记
,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/cdefe767533b3368858d21233e65bf59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e26faf2d524402fefa06823506d1971.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/216876de04325fd250c38c485cbc34b7.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)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】已知公差不为0的等差数列
的前
项和为
,且
,
,
成等比数列,
.
(1)求
的通项公式;
(2)若
,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/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daf464629fa321a6ff7401ab79f07083.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7da2f386b78cdf6489efaa2f5820d3e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ba868f98578a55b1b38c3fb80aa5c17.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbc095ceed420014bfcdd1681454670b.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)
您最近一年使用:0次
解答题-问答题
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(0.65)
解题方法
【推荐2】设数列
的前
项和为
,若
,且
.
(1)求数列
的通项公式;
(2)设数列
的前n项和为
,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/d8cea2f6c2ce146c6aa2774bcd497d34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b008e35e4367db818d464d31bd2248c.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)设数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3819480e1e624208f729ad8653e4f24f.png)
您最近一年使用:0次
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适中
(0.65)
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解题方法
【推荐1】已知数列
中,
为数列
的前n项和,若对任意的正整数n都有
.
(1)求a的值;
(2)试确定数列
是不是等差数列;若是,求出其通项公式,若不是,说明理由;
(3)记
,求数列
的前n项和
.
(4)记
是否存在正整数M,使得不等式
恒成立,若存在,求出M的最小值,若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba26916329d7472ea26f2ff5cf5a733c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8b15fd3a64ad5b695a1a4b0e4225466.png)
(1)求a的值;
(2)试确定数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
(3)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2f7d0b329709c40a47a9dee90d86b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de90e06c720bb070f3fa01b454e8f0c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
(4)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e02ac07429bb02a535dd3f66690eb85.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9f30bc0b571771faa6dc68dbc5469f3.png)
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【推荐2】去年某地产生的生活垃圾为20万吨,其中6万吨垃圾以填埋方式处理,14万吨垃圾以环保方式处理,为了确定处理生活垃圾的十年预算,预计从今年起,每年生活垃圾的总量递增5%,同时,通过环保方式处理的垃圾量每年增加2万吨.
(1)请写出今年起第n年用填埋方式处理的垃圾量
的表达式;
(2)求从今年起n年内用填埋方式处理的垃圾量的总和
;
(3)预计今年起10年内,哪些年不需要用填埋方式处理生活垃圾.
(参考数据:
,
,
)
(1)请写出今年起第n年用填埋方式处理的垃圾量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c59e7c7a84a4bdb959e95536d0404ceb.png)
(2)求从今年起n年内用填埋方式处理的垃圾量的总和
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(3)预计今年起10年内,哪些年不需要用填埋方式处理生活垃圾.
(参考数据:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/875b3fff2a032bced78890ff98d8d235.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35a65620024c4a7801f9a67e84c2bd6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28bd9c2f2e61ab79310731f736681f93.png)
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