已知
为数列
的前
项和,
.
(1)求数列通项公式
;
(2)设
,且数列
的前
项和为
,若
求使
恒成立的
的取值范围
![](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/757fc1cc5116bf9a1bd6b2089f5a3aee.png)
(1)求数列通项公式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abc6af38492f33ed7472e209c76538f5.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/6bd9736828195f010db4e1f0a9dea7a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4fdc5a033312a0a686172005d1973e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
2021·辽宁·模拟预测 查看更多[2]
更新时间:2021-06-18 09:51:22
|
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解答题-问答题
|
适中
(0.65)
解题方法
【推荐1】已知正项数列
的前
项和
,满足:
.
(1)求数列
的通项公式;
(2)设
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16d1a511265fdde77ed111876f337458.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/71e3fada69fbdbf095b43d1367df81bb.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16d1a511265fdde77ed111876f337458.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a4a67138f29758d025473086601cef0.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)
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
解题方法
【推荐2】数列
前
项和为
,满足
,数列
为等差数列且
,
.
(1)求数列
和
的通项公式;
(2)若
,求数列
的前n项和Tn.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.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/5130ec599ed05c7f98f48fa147791834.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9a09e50d4c276fab52d0999bb5cf329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a77da75f741a7abb8d6c5c8fcff06586.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fce83115a50f99e08e9a2db7267aeed.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35f783dd7778f7e2aae2da4edec6dbe7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/38ef4c4439b36c2847b0056a116d56d4.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】已知数列
的前
项的和为
且满足
,数列
是两个等差数列
与
的公共项组成的新数列.
(1)求出数列
,
的通项公式;
(2)求出数列
的前
项的和
.
![](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/03f280c1dbd43e8dca6b4c24228cb27f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b8049fad2f0f69fa78a2e20dcf7e8e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3dd82f4357d915504c89ffa769019529.png)
(1)求出数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)求出数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5344eadd4711db34e3f935aedd5fb270.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
解答题-问答题
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适中
(0.65)
【推荐2】已知数列
是公差为2的等差数列,数列
满足
,若
时,
.
(Ⅰ)求
的通项公式;
(Ⅱ)设
,求
的前
项和
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43b7e7cd571c8cd141cbbfe5d0890bf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa91b5450e4a0719ad59bf86379ce9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cea4ac187cbb465180e89f38250b3970.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/227d0a1ecf1da74833d5487d15bae947.png)
(Ⅰ)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43b7e7cd571c8cd141cbbfe5d0890bf6.png)
(Ⅱ)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac07953530e3c248b3438fb200fb1661.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c88a7ef007c78a93e33bd77c4396626.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
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【推荐1】已知各项均为正数且递减的等比数列
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(1)求数列
的通项公式;
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.若对任意的
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![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fc04ff1d1a0bd3ad109db76fddd9cd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ca2bc66177a1479e24eeaa63b18ba5b.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/314501f06c7e4bf3112fe41ecac7be68.png)
![](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/481db59092a2453cabe1a5dbf40e9b39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/702e86135fb30f7eb169bc8e7a10171a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
您最近一年使用:0次
解答题-证明题
|
适中
(0.65)
名校
解题方法
【推荐2】已知数列
的前
项的和为
,且
.
(1)当
时,求证数列
为等比数列,并求
的通项公式;
(2)当
时,不等式
对于任意
都成立,求
的取值范围.
![](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/b3d5b24fdf64262c644c5b0835970c7c.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b34541e7808f41e34db4b6650e5442c2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f774872ffec6c34cadeb450cfefdb11e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b62713c4fb6c157258886771564124e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ab6197adad4c77dd5b7aa5977a0fd7f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75acc0ce90e233915c66b3ba17618f58.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
您最近一年使用:0次