1 . 设
是正项数列,且其前
项和为
,已知
.
(1)求数列
的通项公式;
(2)令
,求
的前
项和
.
![](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/fd8f84c1be86db7461d5c1e52ec57e7c.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37cca7aa9f28670611bff03afa29edb1.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
名校
解题方法
2 . 已知数列
为等比数列,
是它的前
项和,若
,且
与
的等差中项为
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe229b24e2d56ff6b491725ceae4ff2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b708c8dcb2d66eb2ce0b3718a9cd924a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/622f568f2c2cb8740cc685c8ffe6571c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d199f9235e3bd36bfa78c3772e941896.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eaf33e141c0066c8d5fcaf5d47b7a6e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/effe2fa26816d2d1aa79a51f7f243e1e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2feebb21d486f598ab4f5dfaa3b657fc.png)
A.35 | B.33 | C.31 | D.30 |
您最近一年使用:0次
名校
3 . 设等差数列
的前
项和为
,公差为
,
,
,
,则下列结论正确的是( )
![](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/5c02bc0c74292b1e8f395f90935d3174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/390636a89883bd64bf8da9bf8654aff9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/948d42e08a69266bed4b18ef1af72427.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03a1e385bd995da60cad02a4236d9163.png)
A.![]() |
B.当![]() ![]() |
C.数列![]() ![]() |
D.记数列![]() ![]() ![]() ![]() |
您最近一年使用:0次
名校
4 . 若对于任意
,关于
的不等式
恒成立,则实数
的取值范围是__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4921923069c4f38a0af1ff8637e35b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb81125093294fc6ecf59f0d666ff529.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
您最近一年使用:0次
名校
解题方法
5 . 设正实数
,
满足
,则下列说法正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bbc5b4357fd97fc6a2328953fe45a294.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
您最近一年使用:0次
6 . 在△ABC中,若角A,B,C的对边分别为a,b,c,则△ABC的面积
,其中
,称该公式为海伦公式,该公式可推广到平面四边形:若四边形ABCD内接于圆E,且四边长分别为a,b,c,d,则四边形ABCD的面积
,其中
,若面积为
的四边形ABCD内接于圆E,
,
,点C,D在x轴上方,且
,
,则圆E的标准方程为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8dab06d51bc8c3b659ba7abaa67c6f2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0f2d50ca5cc415bf6721faf2221d626.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3f3d5d27c3574355097050c813ebe8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/575008e0b065f0d535251a041203f99f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e7dc603317eb90974c75efec9f02b1b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0929421a6188c3122442866b0b85a5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54fe2c124d5bbbbe666ee145cd454b6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89488b28105f7612b3da3b90c1b935e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c7fcbc06a3269890bb9971a48ac2d35.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
您最近一年使用:0次
名校
解题方法
7 . 从
中选取
个不同的数,按照任意顺序排列,组成数列
,称数列
为
的子数列,当
时,把
的所有不同值按照从小到大顺序排成一列构成数列
,称数列
为
的子二代数列.
(1)若
的子数列
是首项为2,公比为2的等比数列,求
的子二代数列
的前8项和;
(2)若
的子数列
是递增数列,且子二代数列
共有
项,求证:
是等差数列;
(3)若
,求
的子二代数列
的项数的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/858911660b233271d57b17e358232d45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cc35d18037c40fec3a643a8a0ee1475.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a227a694dc404d1184578c7d278fd8d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/208dfb2f585802ed32c822b6a4005e83.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b13ee542834ccbb57fcc55b1680ca9db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a227a694dc404d1184578c7d278fd8d7.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a227a694dc404d1184578c7d278fd8d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41dddcf7969f39b244b58951c441b62b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a227a694dc404d1184578c7d278fd8d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a227a694dc404d1184578c7d278fd8d7.png)
![](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/432851e0d0b7a2924da29b9cc5ca1706.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc7c9137c7f1f0ce38a3b0cfd6d28696.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a227a694dc404d1184578c7d278fd8d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
您最近一年使用:0次
8 . 定义“等方差数列”:如果一个数列从第二项起,每一项的平方与它的前一项的平方的差都等于同一个常数,那么这个数列就叫做等方差数列,这个常数叫做该数列的方公差.设数列
是由正数组成的等方差数列,且方公差为2,
,则数列
的前
项和
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4a08a83da9efdc92426f98025a9b877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aedee4a77cf7c0d878bae8acb429004b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04c2864e2ec3416cc4c081ac1f71a0af.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
解题方法
9 . 已知数列
的前n项和为
,且满足
.
(1)求
及
;
(2)若
,求满足条件的最大整数n的值.
![](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/f45f16c10ebebdfea2aae2029c94d131.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec4dce359876d43a468b772000795c8b.png)
您最近一年使用:0次
名校
解题方法
10 . 已知数列
为等差数列,且
,
.
(1)求数列
的通项公式;
(2)设
,数列
的前n项和为
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23005bd2386f15812ce36833200d019d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a0a6acd7996ccc71570b11bd081be48.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e7b18da12fab639e07f4ba3fa28a14b.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/08299124b1d23c57a0fb290e0564b34b.png)
您最近一年使用:0次