1 . 已知
均为等差数列,且
,
,
,
,则由
公共项组成新数列
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62e567d7e9761951a266953c8d5042ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18d8e8f821111de8075e5c3dfb22a5d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3859890e300f470dcf4a215249da07e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6abbd310bfce5fc6df04add486e95070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1fde8b4ed7f638dea2bffbc17d0ac51b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62e567d7e9761951a266953c8d5042ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2073e8d431b4364f737badfd0c058dc9.png)
A.18 | B.24 | C.30 | D.36 |
您最近一年使用:0次
解题方法
2 . 已知等差数列
的前
项和为
,且满足
.
(1)求
的通项公式;
(2)记
,求
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.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/d8d6f5b8045fa12951015eb691af793c.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbcdb5dc760e87ec2d5d33e0d2cbf57d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.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
3 . 等差数列
中,
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42f68033c1b49f0c52daefd870c166ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69c3589ef454591e156910f94330af34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b8622956cdfdf378d6d25ae414176a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42f68033c1b49f0c52daefd870c166ad.png)
A.5 | B.6 | C.8 | D.10 |
您最近一年使用:0次
4 . 已知
是公差为3的等差数列,
是以2为公比的等比数列,则数列
的公差为__________ ,数列
的公比为__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/098d9e65e9676e4386c5d861c8eb03b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe3950135dc23925ff9b13212a10eb36.png)
您最近一年使用:0次
5 . 已知
,
是公差分别为
的等差数列,且
,
,若
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c2cce76f37e2fc64bc9891e374782e6.png)
__________ ;若
为等比数列,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4654faacbaac4992a17ec251ef394a9.png)
__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf2f1c1409a06278e847e6b573cef254.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ada14d2413518a353ff8a517875f3f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/654378ad47de00a25d1bcb4840ce7ebd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/211ed64d3f43ffb26dc79b8f18dcbf6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06c7f1717130cfa702690cddadbaccca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c2cce76f37e2fc64bc9891e374782e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8bc5d10484bd7ecd36924b654e80090d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4654faacbaac4992a17ec251ef394a9.png)
您最近一年使用:0次
名校
6 . 已知等差数列
的前
项和为
,且
,
.
(1)求
;
(2)记
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.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/dd478b1ba0e42545b45d505e2e84a140.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc91e27c7410472197be18c0ed2ebb3f.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(2)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aac2b0ad65019880b510c3b6e2a5939a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
您最近一年使用:0次
2018-04-25更新
|
1072次组卷
|
3卷引用:浙江省余姚中学2017-2018学年高一4月质量检测数学试题
解题方法
7 . 设数列
是公差为
的等差数列,
.则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3f7fda69e2b32b9ced2239f915fa59b.png)
______ ;数列
的前
项和
取得最大值时,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f3cb8d72bb2e281b943b3b430138ef7.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a17d5307fe708f59176cb88c50ebd33.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3f7fda69e2b32b9ced2239f915fa59b.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/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f3cb8d72bb2e281b943b3b430138ef7.png)
您最近一年使用:0次
12-13高一下·湖北黄冈·期中
8 . 首项为
的等差数列,从第10项起开始为正数,则公差
的取值范围是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd701839451bde3c9dff71cf92fa40d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
名校
9 . 已知
为等差数列,若
,
,则
的值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2693734765399876e9e93cdb110231c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7da6e97248df8f138ebe684c40c950c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2017-11-12更新
|
240次组卷
|
4卷引用:2014-2015学年浙江省台州中学高一下学期期中考试数学试卷
12-13高一下·浙江绍兴·期中
名校
10 . 在等比数列
中,已知
,等差数列
满足![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3266852fcc5678ecc44a9297ffb3724d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c084525eff8fe028de8670afd16c8f02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3266852fcc5678ecc44a9297ffb3724d.png)
(Ⅰ)求数列与
的通项公式;
(Ⅱ)记,求数列
的前
项和
.
您最近一年使用:0次
2018-01-11更新
|
653次组卷
|
5卷引用:2013届浙江省绍兴市第一中学高一下学期期中考试文科数学试卷
(已下线)2013届浙江省绍兴市第一中学高一下学期期中考试文科数学试卷(已下线)2013届浙江省绍兴市第一中学高一下学期期中考试理科数学试卷2016-2017学年河南郑州一中高二上期中考试文数试卷江西省南昌市2017-2018学年高三第一轮复习训练题数学(七)《等差数列与等比数列》上海市大同中学2016届高三上学期期中(文理)数学试题