1 . 在(
)的展开式中,第2项、第3项、第4项的二项式系数成等差数列.
(1)求n的值;
(2)求展开式中的第7项.
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2 . 已知
是各项均为正数的等比数列,
,且
成等差数列.
(1)求
的通项公式;
(2)求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14835bf3f00139ccec0694d0924db795.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/670f89eafcb08a29915a0d4361031c6c.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
(2)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b7bb5000adef715be512d2ce5ee66f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
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2023-06-14更新
|
416次组卷
|
2卷引用:北京市第二十中学2022-2023学年高二下学期期中考试试卷
名校
解题方法
3 .
中,角
所对应的边分别为
,且
.
(1)求角
的大小;
(2)若
的面积为
,边
是
的等差中项,求
的周长
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/157904a631cff4e8edc86bd7e83c13c1.png)
(1)求角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41322821ce31416fdac8dd6e0aa41c71.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9a475fec8ded321e10a6697319fb975.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
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2023-06-13更新
|
370次组卷
|
2卷引用:安徽省泗县第一中学2022-2023学年高二下学期第二次月考数学试卷
名校
4 . 已知随机变量X的分布列如下表:
若
成等差数列,则公差d可以是( )
X | 0 | 1 | |
P | a | b | c |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
A.![]() | B.0 | C.![]() | D.1 |
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5 . 设
为等差数列
的前
项和,若
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dbd9ff686703cad03aa383e5fec21.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/a9875b5a21e007035dbf079af4617d3b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a4363b3413803d6fcdfb659af41c390.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dbd9ff686703cad03aa383e5fec21.png)
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6 . 在等差数列
中,
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64e2c05dfadd42bca0570af1ea416540.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa906e7ed27950fca3b2edabfd31fccf.png)
A.36 | B.48 | C.60 | D.72 |
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名校
7 . 已知等比数列
的公比为2,前
项和为
,且6,
,
成等差数列,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/614306cc3f34bdee4d5d885b79667645.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/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f65fc200f10b97588a0c9896277c9c64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/614306cc3f34bdee4d5d885b79667645.png)
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2023-06-02更新
|
648次组卷
|
5卷引用:陕西省西安市铁一中学2022-2023学年高二下学期期末理科数学试题
8 . 在等差数列
中,若
,
,则
等于 ( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54f0c12fb05c1c8934b328d3daf0ee29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1d0932cb3f8782d61564a3916e48593.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e35eeaabd951fb09b2926807da3685b.png)
A.20 | B.18 | C.16 | D.![]() |
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22-23高二下·全国·课后作业
解题方法
9 . 已知数列
满足
,且
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0382b4a2ab0657d2d6830bb6be2b17b6.png)
________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17c0886362228655cb93f421d6abf4cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f058265d2335368907242d3d5ac4134.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0382b4a2ab0657d2d6830bb6be2b17b6.png)
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名校
10 . 从冬至日起,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长度依次成等差数列,冬至、立春、春分这三个节气的日影长度之和为
尺,前九个节气日影长度之和为
尺,则谷雨这一天的日影长度为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/870f857243dcbf06309cdb2dff78362f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c2a3fba7f5975478c422e85bd070688d.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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