lqlrs的个人空间

lqlrs： 高三数列

1. 已知数列{an}满足a1=1,a2=3,An+2=3An+1--2An [n属于N*]1. 证明：数列{an+1--an}是等比数列。2 求数列{an}的通项公式？

2008-06-06 23:40 来自版块 - 

lqlrs： 还是数列

1 设sn为等差数列{an}的前n项和，s4=14,s10---s7=30,则s9=_________ 2 等比数列{an}的前n项和为sn，已知s1,2s2,3s3,成等比数列，则{an}的公比为————————？

2008-06-06 22:31 来自版块 - 

lqlrs： 还是数列

1 设sn为等差数列{an}的前n项和，s4=14,s10---s7=30,则s9=_________ 2 等比数列{an}的前n项和为sn，已知s1,2s2,3s3,成等比数列，则{an}的公比为————————？

2008-05-19 19:32 来自版块 - 

lqlrs： 高三数列

1. 已知数列{an}满足a1=1,a2=3,An+2=3An+1--2An [n属于N*]1. 证明：数列{an+1--an}是等比数列。2 求数列{an}的通项公式？

2008-05-19 19:17 来自版块 - 

lqlrs： 高三数列

1. 已知数列{an}满足a1=1,a2=3,An+2=3An+1--2An [n属于N*]1. 证明：数列{an+1--an}是等比数列。2 求数列{an}的通项公式？ 第一步我已经知道怎么做了！只是不知道第二步？请指教！！！

2008-04-20 20:44 来自版块 - 

lqlrs： 名词性从句

1 ---Do you remember ______he came? ---Yes. I do . He came by car. A. how B when C that D if2 I remember _____this used ... 全文

2008-04-19 19:08 来自版块 - 

lqlrs： 状语从句二

1 Although he is considered a great wriyer,________. A his works are not widely read B but his works are not widely read C however his wo... 全文

2008-04-16 12:57 来自版块 - 

lqlrs： 还是数列

1 设sn为等差数列{an}的前n项和，s4=14,s10---s7=30,则s9=_________ 2 等比数列{an}的前n项和为sn，已知s1,2s2,3s3,成等比数列，则{an}的公比为————————？

2008-04-15 23:52 来自版块 - 

lqlrs： 数列

2008-04-15 23:44 来自版块 - 

lqlrs： 状语从句

1 ——————has taken part in the Athens Olpmpic Games is worth praising no matter ___________he or she won medals or not. A Who; if B An... 全文

2008-04-15 23:36 来自版块 - 

lqlrs： 补充句子

用适当的连接代词或连接副词填空： 1 China is no longer________ it used to be. 2 I am very interested in ____________he has improved his pronunciation in su... 全文

2008-04-13 22:41 来自版块 - 

lqlrs： 请教老师

下面是改错题，不知是否有改错！请老师帮忙，顺便说下改错的技巧何在？ 原题是： Dear Mr.Brown, I am writing to thank you ... 全文

2008-04-12 21:00 来自版块 -