1 . 证明:(1)
(k≥2,k∈N);
(2)分别以1,
,
,……,
,……为边长的正方形能互不重叠地全部放入一个边长为
的正方形内.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7251100b5bca08f0a2db2ebc9cfad55b.png)
(2)分别以1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee6a2eba56d4f2d1670b0256b8d86b92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4b8503f4706b8321e4e79a87eadea84.png)
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2 . 已知等差数列
及
.设An=a1+a2+
+an,Bn=b1+b2+
+bn,若对
,有
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04b468786c8644db94f4aa5b781478f3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29518f13a1ebc3fff8181c2d7cfba22f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2448cf72af76b810310e4cfb9818e2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daa5e9bd516f6282483b92cfe6074623.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daa5e9bd516f6282483b92cfe6074623.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/daca83a7d5dd024f1b7338df1377bf48.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a67649ce7b7b3f072c6810fb0108065.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04b468786c8644db94f4aa5b781478f3.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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2014高三·湖南·竞赛
3 . 若
为等差数列,首项![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74c1e527af78cf001c93ab7a3f31128d.png)
则使前
项和
成立的最大自然数
为( ).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74c1e527af78cf001c93ab7a3f31128d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6a6666b035b6092a37d94d9494584e1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49763402b2f2023f0ba64c37924267d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
A.4025 | B.4026 | C.4027 | D.4028 |
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4 .
,
,…,
是互不相等的自然数.证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/610c6d0f613a10e8da6e1fd2d590afb0.png)
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/610c6d0f613a10e8da6e1fd2d590afb0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea72fdc41dd1e14adcda2b1fab2d49ca.png)
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5 . 一个三位自然数
称为凹数,如果同时有
及
(例如104,525,849都是凹数,而123,684,200都不是凹数).则所有凹数的个数是_________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ccdf330c4c11abc1ecfe06660fc178c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43ade3a1d01605706801e238726e55fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f190b83b8d668d02c4e724f9a0cc2735.png)
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6 . 已知
是公差为
的等差数列,且
.
(1)求实数
,
的值;
(2)若正整数满足
,
,求数组
和相应的通项公式
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/504c515e77e919aa8b1f54d392cb0298.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11e813b670dbc7044534c70961c93faf.png)
(1)求实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
(2)若正整数满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09b9c5ace37d53f2b1ec8c2a6a3d7bd5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1049f55f007f0bd923c36935622ee847.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b49e54432375916b1fe7280189f4abfe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
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7 . 已知等差数列
的前12项的和为
,则
的最小值为________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b3779b4ea5477aebfe85113b0de1d60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90a39e4749c77d443c4ee4c3195e57da.png)
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8 . 给定数列
,且
,则
的值是___________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0a39fe0a3527ae1cf0a394c0086805c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15f667b2d8a8de118cb0fea49dc2e2fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db59c6082aa1b8def03bd61c326d61dc.png)
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9 . 把正有理数按下列规则作成序列:
则数
所在位置的序号是_________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2068eeff3006c0689f26bc3fba1b88cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/43b1d0589ffc0aed6f3b2c6689644e79.png)
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10 . 设
,
,…,
是
个正数,把它们顺序放在圆周上,且满足每一个数去除相邻两数的和都是自然数,令
.证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ae0b861522b18be1753acc4474cbc9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8b928d2210c504b002e5b8d3ea7cba0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31836b0a80c65fd90be26c5a44217eb8.png)
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