题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041619-53060.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041619-91311.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041620-62600.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041620-34983.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041620-58172.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041620-62526.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041621-66933.png)
(1)求数列
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041619-53060.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041620-58172.png)
(2)若数列
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041621-53578.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041621-82939.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041621-53578.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041619-91311.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041621-51517.png)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041621-32622.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041622-67157.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041622-11529.png)
解析
试题分析:解:(Ⅰ )∵ 数列
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041619-53060.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041619-91311.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041620-62600.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041620-34983.png)
∴ 当
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041622-99304.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041622-47031.png)
当
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041623-56316.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041623-15467.png)
故
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041621-32622.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041623-51249.png)
又数列
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041620-58172.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041623-47209.png)
∵
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041620-62526.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041623-39217.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041624-92301.png)
∴
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041622-67157.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041623-51249.png)
(Ⅱ)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041624-56815.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041624-15138.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041624-16305.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041625-33658.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041625-17249.png)
所以
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041622-11529.png)
点评:解决的关键是利用等差数列和等比数列的通项公式来求解通项,同时能利用分组求和法来得到求解,属于基础题。
核心考点
举一反三
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041611-28000.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041611-28000.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041611-91586.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041611-43167.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041611-29021.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041612-76816.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041612-11137.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041612-19514.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041611-28000.png)
A.132 | B.299 | C.68 | D.99 |
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041603-45915.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041603-44800.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041604-27240.png)
A.52 | B.90 | C.49 | D.92 |
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041558-57679.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041558-19308.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041558-14917.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041559-22136.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041558-57679.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041559-72252.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041550-91694.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041550-60855.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041550-56784.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041550-91694.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041550-52119.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041550-62280.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041551-69041.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041551-75497.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041551-76171.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041551-65931.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041543-49648.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041543-18799.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041543-73999.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041543-80403.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041543-51568.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041543-40233.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041543-38065.png)
(1)求数列
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041543-49648.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041543-40233.png)
(2)是否存在常数
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041543-53132.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041544-33243.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041544-71359.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191015/20191015041544-60226.png)
最新试题
- 1下列词语中加点的字,注音全都正确的一组是( )A.框(kuàng)架鸭肫(zhūn)压轴(zhòu)戏涎(xián
- 2如图所示,孔明灯又叫天灯,相传是由三国时的诸葛孔明(即诸葛亮)所发明,现有一孔明灯升空后向着东北偏上方向匀速直线上升,则
- 3木炭、硫、铁丝在氧气中燃烧时产生的共同现象是[ ]A.都产生浓厚的白烟B.都能放出热量C.都有气体生成D.都有蓝
- 4You must _____a schedule. [ ]A. make
- 5怎样才能及时调节自己的不良情绪?____________________________________________
- 63.11日本大地震引起核电站爆炸,人们抢购加碘盐防辐射.而事实上食盐加碘主要是防治地方性甲状腺肿,其理由是( )A.碘
- 7人体血液循环系统由血液、 和 组成。人体尿液形成的两个基本过程包括 和
- 8Prices of daily goods _____ through a computer can be lower
- 9美国南达科他州的一个农民,他种植遗传基因作物,驾驶有全球卫星定位系统的拖拉机;衣阿华州的一家保险公司,它用软件来减少管理
- 10There is ______ "u" and ______ "h" in the word "hour". [
热门考点
- 1已知函数,其中.(Ⅰ)当时,求曲线在点处的切线方程;(Ⅱ)求f(x)的单调区间.
- 2有一气球以10m/s的速度匀速上升到某一高度时,从气球上脱离一物体,这个物体离开气球后,将[ ]A、继续上升一段
- 3已知单质A能从溶液中置换出单质B。下列的分析不正确的是( )A.当A、B都是金属,A的还原性一定比B强B.当A、B都
- 4The little kid _____ the habit of telling lies, which made
- 5的算术平方根是________
- 6将函数y=sin(x+)(x∈R)的图像上所有的点向左平行移动个单位长度,再把图像上各点的横坐标扩大到原来的2倍(纵坐标
- 7阅读理解。 A very important world problem is the growth of po
- 8构成植物种子的胚是由[ ]A.胚根、胚轴、胚芽、种皮四部分 B.胚根、胚轴、胚芽、子叶四部分 C.胚根、种皮、胚
- 9数据5,7,8,8,9,9的众数是( )A.7B.8C.9D.8和9
- 10--- I forgot to do my homework. Don’t tell the teacher. ---