已知等差数列
,公差
,记数列
的前
项和为
,
,
是
与
的等比中项.
(1)求数列
的通项公式;
(2)设数列
.数列
的前
项为
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/812be9806122241c476ba1db516c4823.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/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36183db0759eec0e108274d229fcd00b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc858b7a95c5006a44067022da09f667.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f04c3e7d3b05bcf333d55c1fe74f7197.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d51f9147b8265c0276c1f2c2659197.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbd85b79372dc6e596d465f738c3c300.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f774f1631ef9ce65463458e792bc6a1.png)
更新时间:2020-11-29 18:47:12
|
相似题推荐
解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】(1)记
为等差数列
的前
项和,已知
.求
的通项公式及
并求
的最小值;
(2)已知等比数列
中,记
为
的前
项和,若
,求
的通项公式和实数
的值
![](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/4258139894ede54e0a10019a28eda028.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/08eb71ecf8d733b6932f4680874dbbf3.png)
(2)已知等比数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.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/5f8fefad329d3dc9ec2f6880b2ed99a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
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解答题-问答题
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解题方法
【推荐2】已知数列
是等比数列,数列
是等差数列,且
,
,
,
.
(1)求
和
的通项公式;
(2)设
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59dd6c97d2ee3e74ba5730f1cbcc1d43.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bcbc75e8c78cca18f0b2b2456b3c829.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ddb1c730e6a2e1554d89e7926dcf265d.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e8c47b6141aa25e3e29da4810cdc9b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38ef4c4439b36c2847b0056a116d56d4.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
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【推荐1】新年要到了,高二某生为我吴起高级中学制作了一件目前市面上最省电的
灯饰,如图所示(小圆圈代表发光
灯本图只显示出了前三排
灯总排数不超过15).设计方案如下:第一排1个
灯,从第二排起,每一排比上一排多1个
灯.
(1)写出第n排
灯数
关于
的表达式;
(2)前10排共需多少个
灯.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41b1cb8a0f22051dd046202788d688fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41b1cb8a0f22051dd046202788d688fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41b1cb8a0f22051dd046202788d688fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41b1cb8a0f22051dd046202788d688fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41b1cb8a0f22051dd046202788d688fd.png)
(1)写出第n排
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41b1cb8a0f22051dd046202788d688fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
(2)前10排共需多少个
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41b1cb8a0f22051dd046202788d688fd.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/31/78a407c0-96eb-44ec-afed-9ed852a54f19.png?resizew=130)
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名校
【推荐2】已知数列
是公差为1的等差数列,其前8项的和
.
求数列
的通项公式;
求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe229b24e2d56ff6b491725ceae4ff2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/663786f7f690489548db9b77604c040e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4141b26d2c32655003494a91ad6331b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe229b24e2d56ff6b491725ceae4ff2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65863c1abad833b79c303bfca24f535c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f95149133cbe5ec386a29f9bf6ad1192.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb26cd1601fe7e76e1e2dc0b4909324a.png)
您最近一年使用:0次
解答题-问答题
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适中
(0.65)
解题方法
【推荐1】正项数列
的前
项和
满足:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/806a9750801f80c9a6832b6a8f22d318.png)
(1)求数列
的通项公式
;
(2)令
,数列
的前
项和为
.证明:对于任意的
,都有
.
![](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/806a9750801f80c9a6832b6a8f22d318.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
(2)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5da27adffd039c32bb5b7a8d354dfe3e.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)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a37a59558292ad6b3d0978bfd7484990.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6e502ef3a4bc693b7b97b1483c3bc38.png)
您最近一年使用:0次
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名校
解题方法
【推荐2】记
为数列
的前
项和,已知
.
(1)求
的通项公式;
(2)设单调递增的等差数列
满足
,且
成等比数列.
(i)求
的通项公式;
(ii)设
,证明:
.
![](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/b9aa8c8737223748f099a5c437f3a2cb.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设单调递增的等差数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/385275d29d8c8a7841eaeaa3dfab2cdb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/975a03319e38805eb6e5baa4febe03a4.png)
(i)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(ii)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85ac70d32577ec72558ed5010069c32f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c215db1d8f69757118ad405b78035628.png)
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