1 . 已知等差数列
的首项为1,前
项和为
,且
是3与
的等比中项.
(1)求数列
的通项公式:
(2)若
是数列
的前
项和,求
的最小值.
![](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/eb0f10a8a67a3b6c595745f9a82b45b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d29ed246168b03ba97deedbd0c26d373.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba57c83d526ac308d1461e80fcca9f36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
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2 . 无穷等比数列
满足:
,
,则
的各项和为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8e5dadfc7d9b12bea102cc0ce5bfcc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da2fee763f74f7ff53587c86f545fd8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
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3 . 已知数列
满足:
,且
,
.
(1)证明:数列
是等比数列,并求数列
的通项公式;
(2)若
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b5299d8681e97043a0e449cde0f9731.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9b1d808f2e220696fba4590677ea0f.png)
(1)证明:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b463e643a730e8f11504f135a1400909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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4 . 设
是等比数列
的前
项和,若
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/130aab74cff7810ad14ac2480ff5b929.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/c705ed1d40eb3d40ebadd05dbb645b73.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc737fd79335e429f265108d8dd2504c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/130aab74cff7810ad14ac2480ff5b929.png)
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5 . 已知数列
满足
,
(
,
).又数列
满足
.
(1)求证:数列
是等比数列;
(2)若数列
是严格增数列,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f182ded42160adae3e3494b35f170d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c4ce884babe61ed08cbd06e2a4cc5f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd4613271f782a90ab580131d09d03d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0704f453b2de48d36911f7db496bbf82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfb0270fc6eaeffab97962e5e518a104.png)
(1)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
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6 . 已知数列
的前
项和为
,满足
.记
为数列
在区间
内的项的个数,则数列
的前100项的和为_____________ .
![](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/77ea9f7f80c70ca4a52a050f1d05da09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f64696f60c533ad95dc7890eb902741.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7e8510cf4a62bccaa7d56e46c1c16c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62c320a0619c63a5b650a1a94c0a5679.png)
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7 . 已知
是等比数列,
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf334b1e8cef2312c4c2b918b3e59236.png)
____________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c9b6e51986fe5d7a7265e0e93adcb4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bba9dc6fb3fee2f98c8177d837f00d98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf334b1e8cef2312c4c2b918b3e59236.png)
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8 . 一个弹性小球从30米高处自由落下,每次着地后反弹到原来高度的
处,再自由落下,若这个小球能无限次反弹,则这个小球经过的总路程为________ 米
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eac97e6740365c85ad857aff85cefbe5.png)
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9 . 某集团投资一工厂,第一年年初投入资金5000万元作为初始资金,工厂每年的生产经营能使资金在年初的基础上增长50%.每年年底,工厂向集团上缴
万元,并将剩余资金全部作为下一年的初始资金,设第n年的初始资金为
万元.
(1)判断
是否为等比数列?并说明理由;
(2)若工厂某年的资金不足以上缴集团的费用,则工厂在这一年转型升级.设
,则该工厂在第几年转型升级?
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f93a232c88870d213a7b74a796a1ff4b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
(1)判断
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8be23e4b772df85968e9a0afde88815.png)
(2)若工厂某年的资金不足以上缴集团的费用,则工厂在这一年转型升级.设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c999cfa4c0e1507032047eabaa56ceed.png)
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10 . 正项等比数列
中,
与
是
的两个极值点,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/972a067d9d035b9be7768a2e23dee986.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e29f6ffe091d4f51b3b7c8c9ca88005.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c74fd9b94d7e7c54207580a3823b381a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/972a067d9d035b9be7768a2e23dee986.png)
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