2010高考数学总复习17数列练习题VIP专享VIP免费

2010高考数学总复习数列练习题一、选择题1.在数列55,34,21,,8,5,3,2,1,1x中，x等于（）A.11B.12C.13D.142.等差数列9}{,27,39,}{963741前则数列中nnaaaaaaaa项的和9S等于（）A.66B.99C.144D.2973.等比数列na中,,243,952aa则na的前4项和为（）A.81B.120C.168D.1924.12与12，两数的等比中项是（）A.1B.1C.1D.215.已知一等比数列的前三项依次为33,22,xxx，那么2113是此数列的第（）项A.2B.4C.6D.86.在公比为整数的等比数列na中，如果,12,183241aaaa那么该数列的前8项之和为（）A.513B.512C.510D.8225二、填空题1.等差数列na中,,33,952aa则na的公差为______________.2.数列{na}是等差数列，47a，则7s_________3.两个等差数列,,nnba,327......2121nnbbbaaann则55ba=___________.4.在等比数列na中,若,75,393aa则10a=___________.5.在等比数列na中,若101,aa是方程06232xx的两根，则47aa=___________.6.计算3log33...3n___________.三、解答题1．成等差数列的四个数的和为26，第二数与第三数之积为40，求这四个数.2．在等差数列na中,,1.3,3.0125aa求2221201918aaaaa的值.3．求和：)0(),(...)2()1(2anaaan4．设等比数列na前n项和为nS，若9632SSS，求数列的公比q参考答案一、选择题1.C12nnnaaa2.B147369464639,27,339,327,13,9aaaaaaaaaa91946999()()(139)99222Saaaa3.B43521423(13)27,3,3,12013aaqqaSaq4.C2(21)(21)1,1xx5.B2(33)(22),14,14xxxxxxx或而133313,134(),422222nxqnx6.C332112131(1)18,()12,,2,22qaqaqqqqqq或而89182(12),2,2,2251012qZqaS二、填空题1.85233985252aad2.4971747()7492Saaa3.12651955199"55199199()2792652929312()2aaaaaaSbbbbSbb4.337563310925,5,755qqaaq5.2471102aaaa6.112n111111...242422333log33...3log(333)log(3)nnn211[1()]111122...11222212nnn三、解答题1.解：设四数为3,,,3adadadad，则22426,40aad即1333,222ad或，当32d时，四数为2,5,8,11当32d时，四数为11,8,5,22.解：1819202122201255,72.8,0.4aaaaaaaadd201283.13.26.3aad∴18192021222056.3531.5aaaaaa3.解：原式=2(...)(12...)naaan2(1)(...)2nnnaaa2(1)(1)(1)12(1)22naannaanna4.解：显然1q，若1q则3619,SSa而91218,Sa与9632SSS矛盾由369111369(1)(1)2(1)2111aqaqaqSSSqqq96332333120,2()10,,1,2qqqqqqq得或而1q，∴243q