1 . 设数列
的前
项和为
,且
,
.
(1)求
;
(2)求
;
(3)若对任意的
,
成立,求
的取值范围.
![](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/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28db143f2d86f4db4470ca9e95667a27.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(3)若对任意的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/209559aca6bf32705588b6a40e0b7320.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1db8ef40d523242893ebbce537bf5d74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
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2 . 设数列
的前
项和为
,
,
,则( )
![](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/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eba83359167d8ca8c9eafa8a23f34a92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7acac0a395f2315fdfe7014548dbc033.png)
A.![]() | B.![]() |
C.对任意的![]() ![]() | D.对任意的![]() ![]() |
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解题方法
3 . 已知随机变量
服从正态分布
,若
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/711c92626a97e6b778b3aa86e663ee97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d491a7726909c51fe40594c511a56220.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f01b388d5b5fdc4d2c3e9fe5b66d9bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a87bac357650ddd36a23e550abafba5.png)
A.0.2 | B.0.3 | C.0.5 | D.0.6 |
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4 . 已知随机变量
的分布列如下表:
若
,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![]() | -1 | 0 | 1 | 2 |
![]() | ![]() | ![]() | ![]() | ![]() |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e1f3b71d8babd838c40d0c8ca883548.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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解题方法
5 . 已知函数
.
(1)当
时,求
的极值;
(2)函数
在定义域上为增函数,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c82ae2dff8fe64fb957b4622618a97e2.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd876a2ed79c64bacc3e64b8ee92735e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
(2)函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
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6 . 已知函数
在点
处的切线方程为
,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5828873f8369183faf71181cda5b61d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8262240fd443ffde3d0a0533144d342.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a7a779e7150027ff56c6a2b3f8d2e37.png)
A.2 | B.1 | C.-2 | D.-5 |
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7 . 已知函数
.
(1)讨论函数
的单调性;
(2)当
时,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/184a5ea8e818f3c09fdbff0a610b6118.png)
(1)讨论函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf0086b054ef120408acac806a1b1318.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bec9aa46c5ab9f4be19cb6985bb4222.png)
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8 . 桨校组织部分班级参观博物馆,现已安排了5个班级参观,并且已经确定了5个班级的参观顺序,参观前临时增加了2个班级参观博物馆,现将增加的2个班级插入5个班级之间,要求原5个班级顺序不变,插入的班级即不排在首位,也不排在末位,则不同的插入方法数为( )
A.12 | B.18 | C.20 | D.60 |
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解题方法
9 . 某学校为了丰富学生的课外活动,利用了课余时间举行了课外趣味投篮.在投篮活动中,每位学生投篮若干次,每一次投篮的计分方法如下:第1次投篮,投中得2分,不中得1分,从第2次投篮开始,投中则获得上一次投篮所得分数两倍的得分,不中得1分,学生
参加了投篮活动,该同学每次投篮投中的概率都为
,每次投篮是否投中互不影响.
(1)设
表示学生
前2次投篮的得分之和,求
的分布列;
(2)记学生
第
次投篮所得分数
的数学期望为
,求
,
,
,并猜想当
时,
与
之间的关系式.(不必写推导过程)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f89eef3148f2d4d09379767b4af69132.png)
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
(2)记学生
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c05b9832b09731a574d4a4adf7448de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c2fa24d9bad1700a0527d13fc26dc22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bac0f8fdab0bca9740b19b494c345692.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b259c9a664d1200651b28a97d3036f99.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdce2d79e5cc3bf78a3bb4a3a07f0ce1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/05f494d3ca79c8626493ed0728cd4d7e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1af554aa9625a1c75ad96d9bc3b6c392.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bac0f8fdab0bca9740b19b494c345692.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1103388bf9140bf2b5cde7831a0ad5a0.png)
您最近一年使用:0次
10 . “杨辉三角”是中国古代数学文化的瑰宝之一,最早出现在南宋数学家杨辉于1261年所著的《详解九章算法》一书中.“杨辉三角”揭示了二项式系数在三角形数表中的一种几何排列规律(如图所示),则“杨辉三角”中第30行中第12个数与第13个数之比为__________ .
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