题目
题型:不详难度:来源:
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043848-73789.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043848-92298.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043848-82485.png)
(1)若
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043859-64389.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043848-73789.png)
(2)若
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043859-85001.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043859-18632.png)
① 记
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043900-62044.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043900-71811.png)
② 若数列
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043900-99929.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043900-95764.png)
答案
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043901-96412.png)
(2)①根据等差数列的定义,证明相邻两项的差为定值来得到证明。从第二项起满足题意即可。
②当
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043901-56475.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043901-52133.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043900-99929.png)
解析
试题分析:解:(1)当
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043901-76153.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043901-43469.png)
又
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043902-76066.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043902-82096.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043901-96412.png)
(2)①因为对任意的
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043902-10440.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043902-74146.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043903-15024.png)
所以,数列
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043900-71811.png)
②设
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043903-65121.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043903-50102.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043903-52914.png)
所以,
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043903-73286.png)
即数列
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043904-75178.png)
设
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043904-29100.png)
(其中
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043904-74477.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043904-37089.png)
当
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043904-56003.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043905-72390.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043905-48392.png)
当
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043905-29793.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043905-64689.png)
(Ⅰ)若
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043906-30878.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043906-84182.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043906-49690.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043906-39510.png)
(Ⅱ)若
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043907-46226.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043906-84182.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043907-21502.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043906-39510.png)
综上所述,集合
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043907-39439.png)
当
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043907-41990.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043900-99929.png)
当
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043901-56475.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043907-17914.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043900-99929.png)
点评:主要是考查了等差数列的概念和数列的单调性的运用,属于难度题。
核心考点
试题【已知数列,满足:.(1)若,求数列的通项公式;(2)若,且.① 记,求证:数列为等差数列;② 若数列中任意一项的值均未在该数列中重复出现无数次,求首项应满足的条】;主要考察你对等差数列等知识点的理解。[详细]
举一反三
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043830-93710.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043830-98420.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043831-83211.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043831-12660.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043831-97455.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043831-18068.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043832-51162.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043832-21070.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043756-42343.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043756-10586.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043756-74316.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043756-23371.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043802-79851.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043802-73049.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043803-71819.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043723-60554.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043723-94419.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043724-31472.png)
A.![]() | B.![]() | C.![]() ![]() | D.![]() |
A.1 | B.2 | C.3 | D.4 |
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043703-82730.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043704-75983.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043704-73419.png)
![](http://img.shitiku.com.cn/uploads/allimg/20191012/20191012043704-12933.png)
最新试题
- 1小明利用“十•一”放假从镇江到上海看奶奶,在镇江火车站的列车时刻表如图,经比较,小明选择“D413”次列车,两车均正常运
- 2同一平面上有不共线的三点,以这三点作为平行四边形的三个顶点,作平行四边形,能作出的平行四边形的个数是( )A.1个B.
- 3商业广告在建国初期一度很活跃, 1953年以后业务骤减,日益萎缩,直至文化大革命时期广告事业发展陷于空白。造成这一局面的
- 4听下面一段材料,回答第1-3题。1.What is Susan Welch most probably?A. A tea
- 5读太阳直射点移动轨迹图,完成问题。小题1:秋分日这一天,太阳直射在图中的( )A.①B.②C.③D.⑤小题2:当太阳直
- 6“音乐是流动的建筑,建筑是凝固的音乐。”下面让我们一起来完成有关建筑、城市、与社会发展的探究活动。 【探究一】寻找“凝固
- 7当x=( )时,分式无意义。
- 8(本小题满分12分)从某校高三年级800名男生中随机抽取50名学生测量其身高,据测量被测学生的身高全部在155cm到19
- 9The criminal, as well as some ______ people, was arrested by
- 101920年底列宁多次发表谈话,表达了苏俄希望同各国人民和平共处共存的原则立场,列宁提出这种政策的主要着眼点是 A.苏俄需
热门考点
- 1同温同压下,等质量的N2和CO2相比较,下列叙述正确的是( )A.体积比为8:11B.分子个数之比为11:12C.物质
- 2中东联系的三大洲是( )A.亚洲、非洲、欧洲B.亚洲、欧洲、北美洲C.亚洲、非洲、南美洲D.亚洲、欧洲、大洋州
- 3 --- Are you worried when your son often plays computer game
- 4下列表格中各项都正确的一组是( )类别选项碱盐电解质非电解质A烧碱小苏打BaSO4干冰B纯碱CaCO3NH3•H2OF
- 5已知x,y的值:①x=2y=2②x=3y=2③x=-3y=-2④x=6y=6,其中是二元一次方程2x-y=4的解的是(
- 6最大可能蒸发量是指地表在水分充足的条件下产生的最大蒸发量。下图示意某地1961-1990年间相关统计资料,读图完成下列各
- 7设f(x)=13x+3,利用课本中推导等差数列前n项和公式的方法,可求得f(-12)+f(-11)+f(-10)+…+f
- 8如图,沿波的传播方向上有间距均为1米的六个质点a、b、c、d、e、f,均静止在各自的平衡位置,一列横波以1米/秒的速度水
- 9下列有关质点的说法中,正确的是( )A.研究哈雷彗星公转时,哈雷彗星不可看作质点B.花样滑冰运动员正在表演冰上舞蹈动作
- 10观察下列等式:(第1条)32+42=52(第2条)102+112+122=132+142(第3条)212+222+232