第2章 数列单元测试卷(重点卷)
一、选择题:在每小题给出的四个选项中,只有一项是符合题目要求的.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
A.![]() | B.![]() | C.![]() | D.![]() |
【知识点】 基本(均值)不等式的应用解读
A.![]() ![]() | B.![]() | C.![]() | D.![]() ![]() |
【知识点】 等比中项的应用 等比数列下标和性质及应用
![](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/4ccdc17b603871d20843ffccca2df0ae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce35821130b2f1835d98aefb34287d74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0496f142d8ae5acb06e83526eaa3ef87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/701554763bdbbf2689a8dae07608da38.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
【知识点】 等比数列前n项和的基本量计算 错位相减法求和
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3efdcaebc5659dbc8fb66c0b2bbffd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03d2ec1e1323778480788ef971d37138.png)
A.15 | B.19 | C.-19 | D.-16 |
【知识点】 分组(并项)法求和
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced60eeab508479f0e42f0feedefbe97.png)
A.数列{an}是等差数列 |
B.数列{an}是递增数列 |
C.a1,a5,a9成等差数列 |
D.S6﹣S3,S9﹣S6,S12﹣S9成等差数列 |
【知识点】 判断等差数列 由前n项和判断数列是否是等差数列
![](https://img.xkw.com/dksih/QBM/2020/9/17/2551895707279360/2554700229140480/STEM/5b531dbbba1d4ca9848c3b51e89da973.png?resizew=387)
A.S1>S4,S10<S11 | B.S4>S5,S10<S13 |
C.S1<S4,S10>S11 | D.S4<S5,S10>S13 |
【知识点】 确定数列中的最大(小)项
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3468a665ac713ab7b400c672f19650a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee97fe58cbc7c13f845527e8479045a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
A.4 | B.5 | C.6 | D.7 |
【知识点】 等差数列的简单应用 基本不等式“1”的妙用求最值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9fec4792c1a6d2690856deff5288eea0.png)
A.37 | B.-27 | C.77 | D.46 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63d471926f7b27322d90c82b9ce21d3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57b57be76b6cae539d33b395ab457834.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2eaa992a449b828df0ff545e233b279b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5adc71364064a9dfa0151fa6bc67d18.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21d9df07573333c879ca2059c3f4e24c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a41042377b781b28ed7005e58d45abc.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef5b655cbb474e3577346e58c5b0c074.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e684b85018b4098b55a7392abac90cd.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/04c4fb162e3467777ea2c793304d0c68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/758a52fc8496bd4dc3a354c7bfaf84ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4f95463e4696bcb6ed28581bad689d0c.png)
A.![]() | B.![]() | C.![]() | D.![]() |
【知识点】 裂项相消法求和 利用an与sn关系求通项或项
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/828824cda0f08a6b58053187d39d980a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/990641ac6a3b81cfa4fc0c86e84c6a88.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7e83a3e2582a1946a9156f59846c7dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb10f418620f7be1f8c7e94fb0b7a0fb.png)
A.![]() | B.![]() | C.![]() | D.![]() |
【知识点】 导数的运算法则 无穷等比数列各项的和 计算古典概型问题的概率
二、填空题
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29fa0e0526598c4140789f6328daac9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4754fbe523ca63eba3810a3f88f37df3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
【知识点】 直线方程的实际应用 求点到直线的距离 坐标法的应用——点到直线的距离
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb4ff87bece1c914a36c1358964d882d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c90282d4a37c9a20620d4bbb0c263cae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e3928a18a0eb2eceb0e2c53f01dae07.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/441e52bc18bd6069122f39a5d43e6d03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f0cf516bcd5d29723309bea709024cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3d7f720e80c8fe0ac2093814d0534cb.png)
【知识点】 由定义判定等比数列 等比数列通项公式的基本量计算
【知识点】 等比数列下标和性质及应用
三、解答题
(1)求S9
(2)记bn=|an|,求数列{bn}的前9项和T9.
【知识点】 含绝对值的等差数列前n项和
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6df1038200f2d97a52c716aab6c3bcb6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acce76e9f4eada0ce411e19bef596488.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64050dbea86fd9fb24a897deb39584fa.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/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5e8a0556dfebe574a48ddd3a34dab11.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/71dd529d39504403bea1bb64f6d65965.png)
(2)令
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9028307dbfd250025da49984a3a9dd5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdefe767533b3368858d21233e65bf59.png)
(Ⅰ)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(Ⅱ)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1b6a2abf80a418356a66f1e9f03c090.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
【知识点】 写出等比数列的通项公式 等比数列通项公式的基本量计算 裂项相消法求和
(1)求an,Sn与Tn;
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cfd2ac66b3882ecf957fdb54c795b79.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c802ec885fb8e64990afa0bfd14cceaa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/492ec5a0383c89c901f3ea4c5c6890e0.png)
(1)求数列{an}的通项公式;
(2)求数列{bn}的通项公式;
(3)设cn=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/462f644c4a74b81d24687e3fc613ec54.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0704f453b2de48d36911f7db496bbf82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fcebcd3a017c1b7b6ac4949ae364ef5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bd9736828195f010db4e1f0a9dea7a4.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/500d68f2678989a5ce7431cfd51b019d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/466e849d4403b1496dc317217b5bc67e.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f2f2d7c81cb44416bcdf59419637682.png)
①设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/221d4aef7e66400524b55da688cc3998.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
②设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a93be947dd2a3d39f8c765027146719.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7db96e3fbf5d638b9bb1b9d0207d104.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23268c90cbd10b805b58348baf1653ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/280c1facefbcdae7a176767e3706b8e1.png)