题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015709-86193.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015709-73327.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015709-38458.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015709-64663.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015709-55506.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015709-24894.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015709-26517.png)
(I)若
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015709-88940.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015710-32351.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015710-64883.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015710-56276.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015710-64246.png)
(II)若函数
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015710-17455.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015710-28496.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015711-20070.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015711-72267.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015711-84114.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015711-54455.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015710-56276.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015711-99604.png)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015711-80945.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015712-52040.png)
(II)对任意的
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015712-64083.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015712-82691.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015712-60917.png)
解析
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015713-42709.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015713-77326.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015713-21840.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015713-75612.png)
由
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015713-70998.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015714-92365.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015714-54321.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015714-57191.png)
又liman存在,可得0<
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015714-65692.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015711-80945.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015712-52040.png)
解法二.由题设知tbn+1=2bn+1,且
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015715-82780.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015715-21854.png)
由
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015715-21199.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015715-97674.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015715-38372.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015716-10140.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015716-30026.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015716-93255.png)
由
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015716-56416.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015717-84272.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015717-10711.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015717-74913.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015714-65692.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015717-94342.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015717-84272.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015717-10711.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015717-72978.png)
解法三:由题设知tbn+1=2bn+1,即
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015718-59028.png)
于是有
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015718-48798.png)
②-①得
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015718-72583.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015718-39973.png)
由
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015719-90838.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015719-36667.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015716-30026.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015719-22664.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015719-51756.png)
又
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015717-84272.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015717-74913.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015714-65692.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015711-80945.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015719-69377.png)
说明:数列
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015720-89991.png)
(Ⅱ)证明:因为
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015720-63597.png)
下面用数学归纳法证明
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015712-82691.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015720-44989.png)
(1)当n=1时,由f(x)为增函数,且
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015720-60989.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015721-55962.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015721-89311.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015721-18181.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015721-21655.png)
即
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015722-72091.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015722-30036.png)
(2)假设n=k时结论成立,即
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015722-32855.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015722-69766.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015722-58408.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015722-69766.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015723-32995.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015723-89792.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015722-58408.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015723-89792.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015723-51664.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015723-79412.png)
这就是说当n=k+1时,结论也成立.
根据(1)和(2)可知,对任意的
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015712-64083.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015712-82691.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015712-60917.png)
核心考点
试题【(本小题满分12分)已知数列,与函数,,满足条件:,.(I)若,,,存在,求的取值范围;(II)若函数为上的增函数,,,,证明对任意,(用表示).】;主要考察你对等差数列等知识点的理解。[详细]
举一反三
已知各项全不为零的数列{ak}的前k项和为Sk,且Sk=
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015655-19653.gif)
(Ⅰ)求数列{ak}的通项公式;
(Ⅱ)对任意给定的正整数n(n≥2),数列{bk}满足
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015655-53282.gif)
求b1+b2+…+bn.
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015647-34673.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015648-12420.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015648-90862.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015648-45944.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015648-56716.gif)
A.2009 | B.2010 | C.4018 | D.4020 |
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015641-39348.gif)
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015642-22644.gif)
A.1 | B.2 | C.3 | D.4 |
![](http://img.shitiku.com.cn/uploads/allimg/20191013/20191013015611-37644.gif)
最新试题
- 1填补下列名句的空缺处或按要求填空。(1)《望岳》中表达站得高望得远这种思想境界,蕴涵着深刻的哲理,给人以启示的两句话是
- 2礼仪是个人、集体、国家精神文明的象征。关于礼仪,正确的说法是 [ ]A.现代礼仪和传统礼仪之间有条鸿沟,不可逾越
- 3水平地面上放一个重为200N的铁块,铁块与地面间的最大静摩擦力大小为63N,铁块与地面间动摩擦因数为0.3,一个人用水平
- 4(8分)简答题胡锦涛总书记在中央扶贫开发工作会议上指出:“贯彻落实科学发展观,到2020年深入推进扶贫开发的总体目标是:
- 5一氧化碳和二氧化碳都具有的性质是( )①难溶于水;②无色气体;③都能与氧化铜反应;④都能与澄清的石灰水反应.A.②B.
- 6 The chief editor expressed his doubt _______ senior people
- 7每年5月31日为世界无烟日,从今年1月9日起,我国承诺实现公共场所全面禁烟。吸烟有害健康,烟气中的一种有毒气体是A.O2
- 8阅读理解。 My friend, Dick, has a large police dog. Its name
- 9【题文】已知,则________________
- 10根据入射光线和折射光线,完成图甲、图乙光路图:
热门考点
- 1 2010年10月9日在哈市交委会工作会议上传出消息,为进一步规范城。市交通秩序,我市将采取看事故录像、念交通法规、协
- 2云霄枇杷在当地被称为“开春第一果”.从植物体结构层次上看,枇杷果实属于( )A.细胞B.组织C.器官D.植物体
- 3白炽灯泡用久了灯丝会变细,是由于钨丝在高温下发生了 的缘故。
- 4根据拼音写出汉字。确(záo) _____ (chěng)______能 丰功伟(jì)_____ 相
- 5A:Why do Chinese people like red?B:Because they think it can
- 6植物先开花后结果.______.
- 7I’m expecting a pet dog for long,but mom has no time to buy
- 8下列说法正确的是( ).A.原子及其离子的核外电子层数等于该元素所在的周期数B.元素周期表中从ⅢB族到ⅡB族10个纵行
- 9下列属于我国特有珍稀动物的是( )A.金鱼B.白鳍豚C.海豚D.袋鼠
- 10在“文化与一个国家生存和发展的关系”主题讨论会上,某同学提出:“欲灭一国,先灭其文化。”以下判断正确的是①该同学强调了文