解题方法
1 . 已知函数
,
.
(1)证明:
.
(2)证明:
.
(3)若
,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fa6be945eb11c0498223950886460a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d463f5ad0920eaa291f87a5528c53f4.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1d0d3e1b8a17cfb8266d19316c37ed8b.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce084a09377c15254a57339698454923.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fa208de679a96467488aa9655ee1f6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/481f86b6e9c3eb6707a665bb55d18646.png)
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名校
2 . 已知变量y与x存在线性相关关系,根据一组样本数据
,用最小二乘法建立的线性回归方程为
,则下列结论正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d23a8ce02bc62a90c83ae361d580e094.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18e9372a046908377ea106c8f824b554.png)
A.变量y与x具有负的线性相关关系 |
B.若r表示y与x之间的样本相关系数,则![]() |
C.当变量![]() ![]() |
D.当变量![]() |
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3 . 在一个有穷数列的每相邻两项之间插入这两项的和,形成新的数列,我们把这样的操作称为该数列的一次“和扩充”.如数列1,2第1次“和扩充”后得到数列1,3,2,第2次“和扩充”后得到数列1,4,3,5,2.设数列a,b,c经过第n次“和扩充”后所得数列的项数记为
,所有项的和记为
.
(1)求
;
(2)若
,求n的最小值;
(3)是否存在实数
,使得数列
为等比数列?若存在,求出
满足的条件;若不存在,说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf83e20035c3afd6d26ebfd53d768a70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5425108c557f0f21474c045334f97d9c.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dcd08431daac10be93e6fafbc5d4a90.png)
(3)是否存在实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cce224c28ca451c4f105dc3b077736cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
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4 . 小明研究函数
的图象与导函数,经查阅资料,发现
具有下面的性质:若函数
在
上的导函数为
,且
在
上也存在导函数,则称函数
在
上存在二阶导函数,简记为
.若在区间
上
,则称函数
在区间
上为“凹函数”.请你根据以上信息和所学知识,判断以下函数在其定义域上是“凹函数”的有( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4562f3225c98cf5cb11b47d98c9cc9c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/724340d69477c0ec2418c392b22b1cab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/724340d69477c0ec2418c392b22b1cab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4562f3225c98cf5cb11b47d98c9cc9c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4562f3225c98cf5cb11b47d98c9cc9c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/affdb4e0e91ead05b2684c52f341d935.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4562f3225c98cf5cb11b47d98c9cc9c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8df0dd6144e9a30d1a063b690033c3f2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4562f3225c98cf5cb11b47d98c9cc9c3.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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5 . 已知公差不为0的等差数列
,前n项和为
,且
,_____.
现有条件:
;
;
.请从这三个条件中任选一个补充在上面题干中,并解决下面问题.
(1)求数列
的通项公式;
(2)若
,求数列{bn}的前n项和
.
(注:如果选择多个条件分别解答,按第一个解答计分.)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
现有条件:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7fbd39d2e3eeef71b04ec59f74b091e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf003ccc2fd8aa62b0d6a98d0666771a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a603fd1e721cae04e5c5c2014280edba.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/216876de04325fd250c38c485cbc34b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
(注:如果选择多个条件分别解答,按第一个解答计分.)
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6 . 已知数列
满足
,且前12项和为134,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7999465d0e871febde66296a0cbf058c.png)
_____ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24892db4eaa5b54b3fc95dcba529d444.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7999465d0e871febde66296a0cbf058c.png)
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7 . “中国剩余定理”又称“孙子定理”,原文如下:今有物不知其数,三三数之剩二(除以3余2),五五数之剩三(除以5余3),七七数之剩二(除以7余2),问物几何?现有这样一个相关的问题:已知正整数p(p>1)满足二二数之剩一,三三数之剩一,将符合条件的所有正整数p按照从小到大的顺序排成一列,构成数列
,记数列
的前n项和为
,则
的最小值为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87bbdd99442cbbc3b8610793c384af1a.png)
A.16 | B.22 | C.23 | D.25 |
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8 . 函数
的导数
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a37168ef2fcc617d7ab9f4320d8f7fa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbbefef7b3281be333606691debb669a.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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9 . 已知数列{an}的前5项依次为
,则
的一个通项公式为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3f7fda69e2b32b9ced2239f915fa59b.png)
____________________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/12a5dd3afeace11dffe48c4ecde8436f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3f7fda69e2b32b9ced2239f915fa59b.png)
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