名校
1 . 已知等差数列
和正项等比数列
,
,
既是
与
的等差中项,又是其等比中项.
(1)求数列
和
的通项公式;
(2)
,求数列
的前
项和
;
(3)证明:
.
![](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/1198580c2cc0dcdceecbde3c13a0f1d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f65fc200f10b97588a0c9896277c9c64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/161a7b35d1812e6745ae7f7c540cf87a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00ed46928017a7db641fbb2aad8d0745.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/326be0620b9aeb2caeb634aed6646c39.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/08eb71ecf8d733b6932f4680874dbbf3.png)
(3)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58b07548ef912208a0b755f0a2450d34.png)
您最近一年使用:0次
2021-05-28更新
|
906次组卷
|
2卷引用:天津市河东区2021届高三下学期一模数学试题
2 . 已知正项等比数列
,
,
.
(1)求数列
的通项公式;
(2)求数列
的前
项和.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96427f85ddb187e47a15461c26d662e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/735ba43d9bec95a3c62c32d1c1e728e8.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b79a01631b941a560c5dbe143d5fdd45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
您最近一年使用:0次
2021-04-16更新
|
825次组卷
|
3卷引用:2021届新高考同一套题信息原创卷(四)
解题方法
3 . 定义满足以下两个性质的有穷数列
为
阶“期待数列”:①
;②
.
(1)若等比数列
为4阶“期待数列”,求
的公比;
(2)若等差数列
是
阶“期待数列”(
.k是正整数,求
的通项公式;
(3)记
阶“期待数列”
的前n项和为
(
.k是不小于2的整数),求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d02a8555da4dbbc7820a50a95b071ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3444792802dd088cd0cc323483de189b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afa0fca4198a6d5c5b76e5e1716dc4e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f4830a6ec5e0ffd7074b854b4ecdc19.png)
(1)若等比数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若等差数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/394aee19f94c2b70fcce1d69b31dc7fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/851f68e5082033f024ee2012e6ff598c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(3)记
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b5631bc01b998a4b3fabd9e131699dc.png)
![](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/a0a3aa5e30bd2ccac16959d046bb38f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7575a54621b480d9d1e0efa5935d8f47.png)
您最近一年使用:0次
4 . 设递增等比数列
的前
项和为
,已知
,且
,
,
成等差数列.
(1)求数列
的通项公式;
(2)令
,求
.
![](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/4ccdc17b603871d20843ffccca2df0ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7131900393b9906bd6dcfe26ade2059f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/911278aa8595846abac1972e1de59995.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0462c9dc4a0bd08a0ec1cc07f1d2f3e6.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06a1c9153d381d8276809aa13f64c039.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b997fc3f4075377a50bdbf432d5a6d06.png)
您最近一年使用:0次
2020-05-16更新
|
1145次组卷
|
6卷引用:重庆一中2021届高三高考数学押题卷试题(三)