解题方法
1 . 甲口袋中装有2个黑球和3个白球,乙口袋中装有5个白球. 现从甲、乙两口袋中各任取一个球交换放入另一口袋,重复
次这样的操作. 记甲口袋中黑球个数为
,恰有1个黑球的概率为
,恰有2个黑球的概率为
.
(1)求
与
;
(2)设
,求证:数列
是等比数列;
(3)求
的数学期望
(用
表示).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93d0f3799612b81e85b87241ec8eee68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ffb021aa7d5a5c2f0691e337caad624.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ce603aa3abcb61750d2191aaa13dddc.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/358a8d382747e8cde8856bb41f75ebc7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/004119ee12f72bf1516d34c264c2863b.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cadb6805694c8ae6729c2609d20491c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c895d4ce5ce82ef9b311b9369b4de11.png)
(3)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93d0f3799612b81e85b87241ec8eee68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/685a18e8694ab2c3243133d8a1988e68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
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解题方法
2 . 设数列
满足
,则
的值为__________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/255ab415e72920bc175bb6cdcca0351d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d74a0dec73090fe376a78c906193713.png)
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3 . 在数列
中,
.
(1)求证:
是等比数列;
(2)若
,求
的前
项和
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8a387162fd9fd9916724e4bbf36edfd.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c895d4ce5ce82ef9b311b9369b4de11.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6167e15ff5c344afdbebeb6fadb5830c.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)
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2024高三·全国·专题练习
解题方法
4 . 已知数列
和
满足:
,
,
,
,其中
.证明:数列
是等比数列;
![](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/352d9b76dcf639368fa68cae70149802.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5fd705b936f0417aa140f274e195f56b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17c55d3a8147c95e54196a7c0616a02d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d636aca5743fd72bd5f7500b94d2e493.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15a70b95c53fb6655721e2a8c61f5c2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ec12a9a60f82467bf7bf834a9a9b1f7.png)
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2024高三·全国·专题练习
解题方法
5 . 已知数列
满足
,
,判断数列
是否是等比数列?若是,给出证明;否则,请说明理由;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76aef4cdcb5af742ce28003b7b6c8c20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/390636a89883bd64bf8da9bf8654aff9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f359405d7f43b97164eb9ed3e98ce0d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2fa0a9335527f502ff782f35e44a87b8.png)
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2024高三·全国·专题练习
解题方法
6 . 已知数列
满足
,
.令
,证明:数列
为等比数列;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/373cfb2962ca8dd469c689e15e92aaac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a33439e046b785333257f3847d1840dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
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7 . 已知数列
的前
项和为
,且
.
(1)求实数
的值和数列
的通项公式;
(2)若
,求数列
的前
项和
.
![](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/9943ab347857464880b2a945a25acf93.png)
(1)求实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/578c8d256f3f7980b310abc713a901ab.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)
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名校
解题方法
8 . 一只蜜蜂从蜂房
出发向右爬,每次只能爬向右侧相邻的两个蜂房(如图),例如:从蜂房
只能爬到1号或2号蜂房,从1号蜂房只能爬到2号或3号蜂房……以此类推,用
表示蜜蜂爬到
号蜂房的方法数,则
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/652254e05eb410505ea9d1807a4e99c0.png)
A.1 | B.![]() | C.2 | D.![]() |
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9 . 数列
的前n项和为
,且
,则
等于( )
![](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/fb776d1b05eb253d3a5b1fc2f62cd2ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a48e81b54f78b96294295542b010dfb.png)
A.120 | B.122 | C.124 | D.126 |
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名校
解题方法
10 . 近年来,购买盲盒成为当下年轻人的潮流之一,为了引导青少年正确消费,国家市场监管总局提出,盲盒经营行为应规范指引,经营者不能变相诱导消费,盲盒最吸引人的地方,是因为盒子上没有标注,只有打开才会知道自己买到了什么,这种不确定性的背后就是概率,现有玩具店推出四种款式不同、单价相同的盲盒(这四款分别是草莓熊、三丽鸥、蛋仔、卡皮巴拉),每款数量足够多,购买规则及概率规定如下:每次购买一个,且买到任意一种款式的盲盒是等可能的.
(1)现小明欲到玩具店购买盲盒,设他首次买到草莓熊这款盲盒时所需要的购买次数为
,证明:
;
(2)设首次出现连续
次购买到草莓熊这款盲盒时所需的试验次数期望为
,
(i)求
;
(ii)求
.
提示:求
的方式:先进行第一次试验,若第一次试验失败,因为出现试验失败对出现连续两次成功毫无帮助,可以认为后续期望仍是
,即总的试验次数为
;若第一次试验成功,则进行第二次试验,当第二次试验成功时,试验停止,此时试验次数为2,若第二次试验失败,相当于重新试验,此时总的试验次数为
.
参考公式:
(1)现小明欲到玩具店购买盲盒,设他首次买到草莓熊这款盲盒时所需要的购买次数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f022950e0faa45b617d497b01b5292b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d529964557088220060dd7788de99fa.png)
(2)设首次出现连续
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a78b3c84e7818ed70018eea40c72665.png)
(i)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/522230546d4b802094e86ceb48c2ba38.png)
(ii)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49fdf8595b4c2558956134e152b8a4b7.png)
提示:求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b4f150ab98bde511e0f65d9bafab031.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b4f150ab98bde511e0f65d9bafab031.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e599def7fc8d58e1f4f70e3f94e1cb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0f0ab88512620afb30d306754460263.png)
参考公式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a6cccc2739f1ced1f6c4cb0189154ef.png)
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