1 . 设一组样本数据
满足
,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/195f9cb9c1ca84756dd98afdc784ead9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe45ccb5ede3eb19706a6b58f98b3ec8.png)
A.拿走![]() | B.拿走![]() |
C.拿走![]() | D.拿走![]() |
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解题方法
2 . 龙泉游泳馆为给顾客更好的体验,推出了A和B两个套餐服务,顾客可选择A和B两个套餐之一,并在App平台上推出了优惠券活动,下表是该游泳馆在App平台10天销售优惠券情况.
经计算可得:
.
(1)因为优惠券购买火爆,App平台在第10天时系统出现异常,导致当天顾客购买优惠券数量大幅减少,已知销售量y和日期t呈线性关系,现剔除第10天数据,求y关于t的经验回归方程
结果中的数值用分数表示
;
(2)若购买优惠券的顾客选择A套餐的概率为
,选择B套餐的概率为
,并且A套餐可以用一张优惠券,B套餐可以用两张优惠券,记App平台累计销售优惠券为n张的概率为
,求
;
(3)记(2)中所得概率
的值构成数列
.
①求
的最值;
②数列收敛的定义:已知数列
,若对于任意给定的正数
,总存在正整数
,使得当
时,
,(
是一个确定的实数),则称数列
收敛于
.根据数列收敛的定义证明数列
收敛.
参考公式:
.
日期t | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
销售量 | 1.9 | 1.98 | 2.2 | 2.36 | 2.43 | 2.59 | 2.68 | 2.76 | 2.7 | 0.4 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c92127c5138513f69b02d2ba9e1e265.png)
(1)因为优惠券购买火爆,App平台在第10天时系统出现异常,导致当天顾客购买优惠券数量大幅减少,已知销售量y和日期t呈线性关系,现剔除第10天数据,求y关于t的经验回归方程
![](https://img.xkw.com/dksih/QBM/2024/5/26/3505219411517440/3505377059332096/STEM/e3455f6a3a9e4066996d54e0c0a52927.png?resizew=10)
![](https://img.xkw.com/dksih/QBM/2024/5/26/3505219411517440/3505377059332096/STEM/a9629839a0654872852cd4760f3249ee.png?resizew=10)
(2)若购买优惠券的顾客选择A套餐的概率为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56d266a04f3dc7483eddbc26c5e487db.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b2a698891d42c70b597f0da4f215f09.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf83e20035c3afd6d26ebfd53d768a70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf83e20035c3afd6d26ebfd53d768a70.png)
(3)记(2)中所得概率
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf83e20035c3afd6d26ebfd53d768a70.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59a42dac471af0c4f53da171597135ff.png)
①求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf83e20035c3afd6d26ebfd53d768a70.png)
②数列收敛的定义:已知数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/711c92626a97e6b778b3aa86e663ee97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4ccd4537f4dee2050ade38b972eb9b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/985dc26a89252b2e8dea815c529a2ffb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/512e8bacfff15253901cd216a1e42013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c5a325806df1a1c3e7ce609fe99085f.png)
参考公式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86b12fb0fba9df3f7a1796082ce50ae7.png)
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3 . 某企业生产一种零部件,其质量指标介于
的为优品.技术改造前,该企业生产的该种零部件质量指标服从正态分布
;技术改造后,该企业生产的同种零部件质量指标服从正态分布
.
附:若
,取
,
.
(1)求该企业生产的这种零部件技术改造后的优品率与技术改造前的优品率之差;
(2)若该零件生产的控制系统中每个元件正常工作的概率都是
,各个元件能否正常工作相互独立,如果系统中有超过一半的元件正常工作,系统就能正常工作. 系统正常工作的概率称为系统的可靠性.
①若控制系统原有
个元件,计算该系统的可靠性,并判断若给该系统增加一个元件,可靠性是否提高?
②假设该系统配置有
个元件,若再增加一个元件,是否一定会提高系统的可靠性?请给出你的结论并证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bcbf0c9ad1286d411e8f60f2692bbab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5959d97dc5bc3e828e203247145be7c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2c56e37551085c397ab13e76469d879.png)
附:若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1290917c2c835b61384480b335cc1d13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c2e2a3047fd8a303139fffe9af03adf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60b7f96ea125548730b481a99bbe749d.png)
(1)求该企业生产的这种零部件技术改造后的优品率与技术改造前的优品率之差;
(2)若该零件生产的控制系统中每个元件正常工作的概率都是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29c8578f06897aa6fb84aa95c797d3d8.png)
①若控制系统原有
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8860d9787671b53b1ab68b3d526f5ca.png)
②假设该系统配置有
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1296512cba519b673d863c007cc8a82b.png)
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解题方法
4 . 已知数列
前n项和为
,
,
,
,设![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f2f05c09a35346b62d8bdaf95bfaea.png)
(1)是否存在常数k,使数列
为等比数列,若存在,求k值,若不存在,说明理由.
(2)求
的表达式,并证明
.
![](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/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18d8e8f821111de8075e5c3dfb22a5d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3978c147211401cfa8f6f6984d4542a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23f2f05c09a35346b62d8bdaf95bfaea.png)
(1)是否存在常数k,使数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a323ef99ce96bef2781553fdc1c724e.png)
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解题方法
5 . 在三角形
中,角
,
,
的对边分别为
,
,
且满足
,
,则
面积取最大值时,
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8935b83ddf7174d0d12d1053c02cc6c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6de1d395e6c48c0676a1488a299479d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f774cd650f14c8f6e4fe0c6a432768bb.png)
A.![]() | B.![]() | C.![]() | D.![]() |
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6 . 组合投资需要同时考虑风险与收益.为了控制风险需要组合低风险资产,为了扩大收益需要组合高收益资产,现有两个相互独立的投资项目A和B,单独投资100万元项目A的收益记为随机变量X,单独投资100万元项目B的收益记为随机变量Y.若将100万资金按
进行组合投资,则投资收益的随机变量Z满足
,其中
.假设在组合投资中,可用随机变量的期望衡量收益,可用随机变量的方差衡量风险.
(1)若
,
,求Z的期望与方差;
(2)已知随机变量X满足分布列:
随机变量Y满足分布列:
且随机变量X与Y相互独立,即
,
,
.求证:
;
(3)若投资项目X是高收益资产,其每年的收益满足:有30%的可能亏损当前资产的一半;有70%的可能增值当前资产的一倍.投资项目
是低风险资产,满足
.试问
能否满足投资第1年的收益不低于17万,风险不高于500?请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa38dbb8ff74f37f9f30ccc116b25c4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7023775b43da9414a7e0418f1d72bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd3ede869e508a8c8bda34a16782f863.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abdb06b53dc96b293381556f72249756.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/558e11d700481dc414d5d073b4b88a3d.png)
(2)已知随机变量X满足分布列:
X | … | … | |||||
… | … |
Y | … | … | |||||
… | … |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26c6ea36362a2a2be3a305def74b5503.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7023775b43da9414a7e0418f1d72bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b6a75ef99a70ae69f5842779327b59e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7823e1318ceb97a9d1ad9ccac512697f.png)
(3)若投资项目X是高收益资产,其每年的收益满足:有30%的可能亏损当前资产的一半;有70%的可能增值当前资产的一倍.投资项目
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a829fdd8ec0f3b7ede883cf2c3e53b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abdb06b53dc96b293381556f72249756.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1d7b2c91adfc46f34cd682eb9adbbd8.png)
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解题方法
7 . 已知直线
与曲线
和
都相切,倾斜角为α,直线
与曲线
和
都相切,倾斜角为β,则
取最小时,实数a的值为__________________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9b0f5f44abbc6544a2f672b025b013.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cceb23a0b364f57c24ef0cf2fa1612a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01fbe68bc39206e5eee8afa7c15077ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f6f17bc385bafb37e8f964e5eb99cd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cceb23a0b364f57c24ef0cf2fa1612a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01fbe68bc39206e5eee8afa7c15077ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc42b556ad93ff83b8d6464cd9914685.png)
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解题方法
8 . 已知椭圆
的离心率为
,
,
是C的左、右焦点,直线
是其右准线,P是l上的一动点,Q点在C上.
(1)求C的方程.
(2)若直线OQ、PQ的斜率之积为
,平面内是否存在定点T满足
恒成立.若存在求出T的坐标,若不存在说明理由.
(3)若
,过P的动直线与C交于不同的两点M,N,在线段MN上取异于M,N的点H,满足
,证明H恒在一条直线上并求出这条直线的方程.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7d72a07a4e5acfc140a3cea1f26b951.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5989c84e320b504511f23eeb6e7357.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5076289823db419f94e9c0c8f4aafd9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3fb78c5f885034612c0e030b920143d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/495bb3e5a3a9d35f5c9f0cf1f5d51876.png)
(1)求C的方程.
(2)若直线OQ、PQ的斜率之积为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3389f53711264b0acba3ba6019f8b908.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9044578e41bda9021aa36aad1ec6f5a.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d20d74053c83be065c84043bcde76f02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3504c5529a4758c027d925b2cceb1545.png)
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解题方法
9 . 已知
,
,与y轴平行的直线l与
和
的图象分别交于A,B两点,则
的最小值是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18b6458e2d01c96f7e17c4aa52dfa801.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e9f049a5f960728c60a909821b2404b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4669810732b633b60dbeaf0bf57204f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f4dfec890cdfdda355e19463f3be813.png)
A.1 | B.![]() | C.![]() | D.![]() |
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10 . 设
,则( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/698f362a14c0eb70f91c5c4be22082fc.png)
A.![]() | B.![]() | C.![]() | D.![]() |
您最近一年使用:0次