名校
1 . 在等差数列
中,
,则该数列的前
项和
等于______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/701f4e33c69d03bc548b2067ffd553a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5453184e251cfe787b5965cd38426962.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/520f907d998b6ca7466948ab5a7ff76c.png)
您最近一年使用:0次
2020-12-17更新
|
296次组卷
|
3卷引用:陕西省西安市长安区第一中学2020-2021学年高二上学期期中数学(文)试题
2 . 已知数列
为等差数列,
为
的前
项和,若
,
,则
的取值范围是______ .
![](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/1fa8be091508c012442fdb1cd6781ab9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abbb1505f2686127b7d484d8edae8bfc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f30f56664446f32dbbc2c5f12a99374.png)
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3 . 已知等差数列
满足
,
,
的前
项和为
.
(1)求数列
的通项公式及前
项和
;
(2)令
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1928c254cfada1f75a5cd1e34db5a63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/972b777353c3d98f4ba988c827d3896e.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)
(1)求数列
![](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)
(2)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/860e7ce680784abb19edb20bdb9145db.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
2020-12-15更新
|
1205次组卷
|
5卷引用:天津市静海区瀛海学校2020-2021学年高三上学期10月检测数学试题
天津市静海区瀛海学校2020-2021学年高三上学期10月检测数学试题重庆市永川北山中学校2023届高三上学期期中数学试题(已下线)专题24 数列(解答题)-2021年高考数学(理)二轮复习热点题型精选精练(已下线)专题22 数列(解答题)-2021年高考数学(文)二轮复习热点题型精选精练(已下线)专题23 数列(解答题)-2021年高考数学二轮复习热点题型精选精练(新高考地区专用)
名校
4 . 在等差数列
中,已知前21项和
,则
的值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87dd9f50b692e7e44e5779eb7436aaf4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6080206670a435df9e27713bacb65d17.png)
A.7 | B.9 | C.21 | D.42 |
您最近一年使用:0次
2020-12-15更新
|
729次组卷
|
2卷引用:江苏省南通市启东市2020-2021学年高二上学期期中数学试题
5 . 已知等差数列
的前n项和为
,公差为d,且
,
,则( )
![](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/a8a0eecb5b800fce9ae10aed86ffee62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33e6a1b0cf1299008b00be81b739dd99.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2020-12-13更新
|
934次组卷
|
3卷引用:河北省沧州市七校联盟2021届高三上学期期中数学试题
名校
解题方法
6 . 在前n项和为
的等差数列
中,若
,则
( )
![](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/d7a71a39649f8e5fdd35903afd499584.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae9ad4e59d7081cf19021423a984bc29.png)
A.24 | B.12 | C.16 | D.36 |
您最近一年使用:0次
2020-12-13更新
|
1859次组卷
|
8卷引用:陕西省宝鸡市2020-2021学年高三上学期第三次月考数学(理)试题
陕西省宝鸡市2020-2021学年高三上学期第三次月考数学(理)试题黑龙江省哈尔滨师范大学附属中学2021-2022学年高三上学期期中考试数学(理)试题黑龙江省哈尔滨师范大学附属中学2021-2022学年高三上学期期中考试数学(文)试题(已下线)专题17 数列(客观题)-2021年高考数学(理)二轮复习热点题型精选精练(已下线)专题16 数列(客观题)-2021年高考数学(文)二轮复习热点题型精选精练(已下线)专题16 数列(客观题)-2021年高考数学二轮复习热点题型精选精练(新高考地区专用)江西省贵溪市实验中学2020-2021学年高二(三校生)3月第一次月考数学试题(已下线)“8+4+4”小题强化训练(31)数列求和-2022届高考数学一轮复习(江苏等新高考地区专用)
7 . 《周髀算经》中有这样一个问题,从冬至之日起,小寒、大寒、立春、雨水、惊蛰、春分、清明、谷雨、立夏、小满、芒种这十二个节气的日影子长依次成等差数列,若冬至、立春、春分的日影子长的和是37.5尺,芒种的日影子长为4.5尺,则冬至的日影子长为( )
A.4 | B.8.5 | C.12.5 | D.15.5 |
您最近一年使用:0次
2020-12-12更新
|
210次组卷
|
2卷引用:贵州省毕节市实验高级中学2020-2021学年高二上学期期中考试数学(理)试题
名校
8 . 设等差数列
的前n项和为
,若
,
,如
( )
![](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/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c32a54d94ca7db5bebdabfaa1a5f69b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bb7147e313f9d9f67d19ecb5f499c05.png)
A.8 | B.9 | C.10 | D.11 |
您最近一年使用:0次
解题方法
9 . 已知数列
的通项公式是
,在
和
之间插入1个数
,使
,
,
成等差数列;在
和
之间插入2个数
,
,使
,
,
,
成等差数列;
;在
和
之间插
个数
,
,
,
,使
,
,
,
,
,
成等差数列.这样得到新数列
;
,
,
,
,
,
,
,
,
,
,
记数列
的前
项和为
,有下列判断:①
;②
;③
;④
,其中正确的判断序号是______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e4b5779873cb3f4366dbfdb983dec81.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/1bcd5c11234a01e2b3d2861e9b3a3aec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bcd5c11234a01e2b3d2861e9b3a3aec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a65cdaa89ae90492504808aba2737fac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5733622aabd5a8af1ba76716c86b705a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a65cdaa89ae90492504808aba2737fac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5733622aabd5a8af1ba76716c86b705a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37e5531913e2f170465d8df01795cd51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/090426eb29836bc30c006b3739c08057.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e5cbc4ff3ff76f59867618361b8a2f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa76cf9b7e61f025a614dfea37880500.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37e5531913e2f170465d8df01795cd51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/248cbe7c32c92eacf3668e347f07db0f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e5cbc4ff3ff76f59867618361b8a2f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa76cf9b7e61f025a614dfea37880500.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37e5531913e2f170465d8df01795cd51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/248cbe7c32c92eacf3668e347f07db0f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/090426eb29836bc30c006b3739c08057.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43b7e7cd571c8cd141cbbfe5d0890bf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bcd5c11234a01e2b3d2861e9b3a3aec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a65cdaa89ae90492504808aba2737fac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5733622aabd5a8af1ba76716c86b705a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c062d657b4f46adef709cca67d57e88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a4a440aeda69e21034fdc32516094e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/522be4644a91c3ae9f92e4f787a1e959.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daf464629fa321a6ff7401ab79f07083.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37e5531913e2f170465d8df01795cd51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43b7e7cd571c8cd141cbbfe5d0890bf6.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/2fb7b13af8d37d920795ba1027ac8f0e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/88aac10f2e153e84573b9a0b339f8ec8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6aff82afb4916c7570d1819409a4a925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4b5d6ee276bd8263e2a0ddf3bcbdc8d.png)
您最近一年使用:0次
名校
解题方法
10 . 设等差数列
的公差为
,
.且满足
,
.
(1)求数列
的通项公式.
(2)记数列
,求
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07404ab51f404f9411f79bd4f1fde654.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4ce64685821c3e55c07f151996ca8c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36b98ef143f8159f3a7dafa1fd2f2370.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64d958df158fce3465fb91e40b0ee7c8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7b66bda92549d6956bc1a692df0a47f.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/07404ab51f404f9411f79bd4f1fde654.png)
(2)记数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/216876de04325fd250c38c485cbc34b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7b8d543c7d503fc1073503fc1d52faa.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