1 . 已知数列
是首项为1的等差数列,
是公比为3的等比数列,且
.
(1)求
和
的通项公式;
(2)记
为数列
的前
项和,
,求
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9577321bd85f232a0fecb06639171e90.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)记
![](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/97d07eebd34125e621651cd0e8688830.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.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
解题方法
2 . 甲、乙、丙三名高中生进行传球训练.第一次由甲将球传出,传给乙的概率是
,传给丙的概率是
;乙传给甲和丙的概率都是
;丙传给甲和乙的概率地都是
.如此不停地传下去且假定每次传球都能被接到,记开始传球的人为第一次触球者,第
次触球者是甲的概率记为
.
(1)求
;
(2)证明:
为等比数列.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf31876698721a199c7c53c6b320aa86.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b7f8c30a765d615a050930cca542f44.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46dbb6c2b73d0bde7a4fdb732be161c1.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d82a35fbb7db16ff4b3191fbfa79f23.png)
您最近一年使用:0次
3 . 已知等比数列
的首项为1,公比为3,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/802fbc5b6413b06fe2380c8b8a69a1c2.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2024-01-12更新
|
761次组卷
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4卷引用:内蒙古呼和浩特市2024届高三上学期学业质量监测数学(文)试题
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