1 . 设数列
的前n项和为
,且
.
(1)求数列
的通项公式;
(2)设
,求数列
的前n项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/880d168a12a8c7e5aaad255312cd56a1.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f717cf5c0df8f69f10b804c62fe47647.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
您最近一年使用:0次
2020-11-28更新
|
1026次组卷
|
9卷引用:陕西省安康市2021届高三第一次教学质量联考文科数学试题
解题方法
2 . 已知数列
,
满足
,且
为等比数列,
,
.
(1)求数列
,
的通项公式;
(2)设数列
的前n项和为
,求当
时,正整数n的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2d3c1345789da7ad88fb9593f4fd36b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cda61778c609c4462fea72424e7131a8.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)设数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a756238d24afd7e125df3cbe6d31e24c.png)
您最近一年使用:0次
2020-10-23更新
|
534次组卷
|
4卷引用:陕西省安康市2020届高三下学期第三次联考理科数学试题
陕西省安康市2020届高三下学期第三次联考理科数学试题陕西省安康市2020届高三下学期第三次教学质量联考文科数学试题陕西省安康市2020届高三下学期第三次教学质量联考理科数学试题(已下线)调研测试五(A卷 基础过关检测)-2021年高考数学(理)一轮复习单元滚动双测卷
3 . 已知等比数列
的各项均为正数,
,
,则数列
的前10项的和为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4be2164a2c67d6163faee87a10942bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b13a6e1d671215fc96e4bee3541d1096.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4791efdbe1fd0aa82ab88f3a00521087.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/affc1f5b2ee23aa1050686e8d3ca4aab.png)
您最近一年使用:0次
2020-09-04更新
|
651次组卷
|
2卷引用:陕西省安康中学2020届高三下学期仿真模拟数学(文)试题
名校
4 . 已知各项均为正数的等比数列
的前
项积为
,
,
(
且
),则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ccd4162c7d09f970cb77cadacdbe521.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02e1b855a6bf3dcdf63c0368b2fe94f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e8e19e03715b5f6d3d539f1e0f08f34.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67ca5fd57c2c2fcc3c7a574fdd1467d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/406185f4ad8bcd99e23adc8d289088ed.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ccd4162c7d09f970cb77cadacdbe521.png)
您最近一年使用:0次
2020-07-23更新
|
201次组卷
|
3卷引用:陕西省安康中学2020届高三下学期仿真模拟数学(理)试题
名校
解题方法
5 . 在等差数列
中,
,且
、
、
成等比数列.
(1)求数列
的通项公式;
(2)若数列
的公差不为
,设
,求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a164e8742ea18b0409d539cc4f0d5f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c1ccc6c74b8754e9bcbb3f39a11b6f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f65fc200f10b97588a0c9896277c9c64.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c95b6be4554f03bf496092f1acdfbb89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa3b4bf448b42d21b3a2eddb1ada1e0c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
您最近一年使用:0次
2020-10-28更新
|
431次组卷
|
10卷引用:2020届陕西省安康中学高三第三次模拟考试理科数学试题
2020届陕西省安康中学高三第三次模拟考试理科数学试题2020届宁夏六盘山高级中学高三下学期第二次模拟考试数学(文)试题黑龙江省牡丹江市第一高级中学2019-2020学年高三上学期12月月考数学(理)试题黑龙江省双鸭山一中2020-2021学年高二(上)开学数学(文科)试题甘肃省武威第六中学2020-2021学年高三上学期第四次过关考试数学(文)试题云南省砚山县第一中学2020-2021学年高二上学期第2次月考数学试题四川省达州市渠县中学2020-2021学年高二上学期10月月考数学理科试题宁夏固原市隆德县2021届高三上学期期末考试数学(文)试题四川省成都七中八一学校2020-2021学年高二上学期10月月考数学理科试题(已下线)第四章 数列单元测试(基础版)课时训练-【新教材优创】突破满分数学之2020-2021学年高二数学课时训练(人教A版2019选择性必修第二册)
解题方法
6 . 已知公差不为零的等差数列
,
,且
成等比数列.
(1)求数列
的通项公式;
(2)求数列
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1928c254cfada1f75a5cd1e34db5a63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93633795bba1868384d1e5b6d8d4894b.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cfb8091a44e1edbc4dc5274a57cbd0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
您最近一年使用:0次
7 . 已知数列
的前
项和
,数列
满足
.
(1)证明:
是等比数列,并求
;
(2)若数列
中去掉与数列
中相同的项后,余下的项按原顺序排列成数列
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d118b8d7d2fa7d7bb54ae38c9816acdd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b000cbe808c3d9332a8b8f9dc8dd59b7.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e3f946894e21775f9d2b4219ed627eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/686ece75006ad358f23314dc8a246e11.png)
(2)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/513f380e9a4be5ab5ab62092f6803f67.png)
您最近一年使用:0次
8 . 已知衡量病毒传播能力的最重要指标叫做传播指数RO.它指的是,在自然情况下(没有外力介入,同时所有人都没有免疫力),一个感染到某种传染病的人,会把疾病传染给多少人的平均数.它的简单计算公式是:
确认病例增长率
系列间隔,其中系列间隔是指在一个传播链中,两例连续病例的间隔时间(单位:天).根据统计,确认病例的平均增长率为
,两例连续病例的间隔时间的平均数为
天,根据以上RO数据计算,若甲得这种传染病,则
轮传播后由甲引起的得病的总人数约为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a46dbabd4c5c31cbf0c0d857fd36432.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2468403b3eba9e40bfa36f464e927738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8af17034249858aca29b51a359a672c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d91e07104b699c4012be2d26160976a2.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次
2020-06-03更新
|
532次组卷
|
4卷引用:2020届陕西省安康市高三教学质量检测第四次联考数学(理)试题
9 . 已知数列
的前项和为
,且
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d238a52feae87b0778ba324dc144d50.png)
_________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c8b009fbf76ca2ee2f2ca3d730d700c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d238a52feae87b0778ba324dc144d50.png)
您最近一年使用:0次
解题方法
10 . 设
为数列
的前
项和,
,
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5085e3cdef9ea6c564e079f745d6fdb.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acb8569a8c125c9678a3e75c4f1131a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92906e39027c5f92890082114b1b5648.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e5085e3cdef9ea6c564e079f745d6fdb.png)
您最近一年使用:0次
2020-05-05更新
|
263次组卷
|
4卷引用:陕西省安康市2019届高三下学期第三次教学质量联考文科数学试题