解题方法
1 . 数列
中,
,前n项和
满足
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14835bf3f00139ccec0694d0924db795.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89dcd5baab5c8f1be2463b68cfb19852.png)
(1)求数列的通项公式
以及前n项和
;
(2)若成等差数列,求实数t的值.
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2016-12-03更新
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704次组卷
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3卷引用:2014-2015学年湖南省长沙市周南中学高一下学期第三次月考数学试卷
2014-2015学年湖南省长沙市周南中学高一下学期第三次月考数学试卷河北省鸡泽县第一中学2017-2018学年高二上学期第一次月考数学试题(已下线)第2章 章末检测(B)-2018-2019版数学创新设计课堂讲义同步系列(苏教版必修5)
2 .
的内角
所对的边分别为
,已知三个内角成等差数列,且A为等差中项,若
,则
________ .
![](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/2293e25112b028c10edbf063146ecb3a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72511f149a1b13af02d0e1421d3a63a5.png)
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3 . 若三个非零且互不相等的实数
,
,
成等差数列且满足
,则称
,
,
为一个“
等差数列”,已知集合
,则由
中的上元素组成的所有数列中,“
等差数列”的个数为_______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/291c25fc6a69d6d0ccfb8d839b9b4462.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78bb3d30a94431d5be2a8ef45a5904fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c814128ea2139e33db94ea590e7c2223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aec19b68e3add9d5bfcc6269a1855b87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/291c25fc6a69d6d0ccfb8d839b9b4462.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ecfbd80da8a02ceb9d52edb24d1921b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
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4 . 在△ABC中,三边a,b,c成等差数列,B=30°,且△ABC的面积为
,则b的值是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
A.1+![]() | B.2+![]() | C.3+![]() | D.![]() |
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2016-12-04更新
|
358次组卷
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3卷引用:2016-2017学年湖南益阳市箴言中学高二9月月考数学(文)试卷
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解题方法
5 . 某皮鞋厂有一号、二号、三号三个车间进行生产,在今年
月份共生产了
双皮靴,在出厂前要检查这批产品的质量,决定采用分层抽样的方法进行抽取,若从一、二、三号三个车间抽取的产品数分别为
、
、
,且
、
、
构成等差数列.
(1)求第二车间生产的产品数;
(2)已知一号厂生产了
双,若总共抽查了
双皮鞋,从中再抽取两双,求这两双没有在同一个车间的概率.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/371ad7d2f051aaf9811a26294197f8d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
(1)求第二车间生产的产品数;
(2)已知一号厂生产了
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d4f0e3992efedab109b99e6e172e6238.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8d02ea8c4988c5c28ab93f0d70fb55a.png)
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6 . 已知
是定义在
上的偶函数,令
,若
是
的等差中项,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89afce91d954ae0045b9e706c7154c8b.png)
___________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc4d0d09d2aac6c1c55e56321337b034.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74a622b6dd9af118f839ca197e077e6f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89afce91d954ae0045b9e706c7154c8b.png)
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13-14高一下·安徽阜阳·期中
解题方法
7 . 在
中,内角
的对边分别为
,若
,且
是
与
的等差中项,则角![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26308ea6d8f321d27acbd7f9b131f9f1.png)
_________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.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/32711ee0bd61c1306cfb2209965a80d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79b01adc561735ff5be9bb97266918f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c8e5d4f93699f8dcffb0e7840ca5597e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c32e2f2d7147cf1699fbfdef9cf4af74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26308ea6d8f321d27acbd7f9b131f9f1.png)
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8 . 已知非零实数x,y,a,b,x,y分别为a与b,b与c的等差中项,且满足
,求证:非零实数a,b,c成等比数列.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e29f369801a967c5251f9cf8eeb7d438.png)
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9 . 1和5的等差中项是( )
A.![]() | B.![]() | C.![]() | D.![]() |
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2017-07-08更新
|
184次组卷
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3卷引用:湖南省张家界市2016-2017学高一下学期期末联考数学(B卷)试题