1 . 已知集合
,设
是等差数列
的前
项和,若
的任意一项
,且首项
是
中的最大值,
.
(1)求数列
的通项公式;
(2)若数列
满足
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a101d7fe85109e613e4fdff218e32f5.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/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6302fc3e3d1fac960e84950c0e814a19.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fdbfa7a63fdf5717d40c8c9a73ec160.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b18378ba893f1ce0814c9582699ae29.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/166e346727bcaf56431b36ef42594af6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b511d10eb2d2d913d7282778206db331.png)
您最近一年使用:0次
解题方法
2 . 已知圆心在
轴正半轴上的一系列相外切的圆的圆心的坐标为
,且满足
,第
个圆的圆心横坐标为
,这
个圆的面积之比为
,记
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a19af21827ffd49c3842e1443244940e.png)
________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e684bbf8039dc14ea6a402f3478b3aa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/702de74c38885954ec1fff041b0c2f03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3f933f2a8c0a6a2a2903a071c18c9db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a19af21827ffd49c3842e1443244940e.png)
您最近一年使用:0次
3 . 在正整数构成的等差数列1,2,3,4,…中划掉所有与35不互质的项,将余下的项按从小到大的顺序排成一个新的数列
,再按照第k组含有k项进行分组:
,则2012在第____________ 组.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bba749974aa32d75ff1a30cfea9cd72.png)
您最近一年使用:0次
4 . 设数集
,它的平均数
.现将
分成两个非空且不相交子集
,
,求
的最大值,并讨论取到最大值时不同的有序数对
的数目.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7792b201f65ac98064d8e5dedde8c34c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4080789816701756b41811beabb7a40b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/717995559c925685dacedc60be48fd03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f2560cb9529aebec41d09c26f5d3283e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a95d247ffb2774bb7e22708b25daf7f0.png)
您最近一年使用:0次