浮作者辛夷的毛

已知数列{an}d的前n项和为Sn,且an=Sn*Sn-1(n≥2,Sn≠0),a1=2/9（1）求证：{1/Sn}为等差数列；（2）求满足an>an-1的自然数n的集合.帮忙!. 钢铁是怎样炼成的读书笔记400字 钢铁是怎样炼成的读书笔记.400字左右 钢铁是怎样炼成的读书笔记400字的 , Sn为数列{an}的前N项和,a1=2/9且an=Sn·Sn-1(n>=2)(1)求an的通项公式；(2)n为何值时,|Sn|最大?并求其最大值. 英语翻译 英语翻译 英语翻译 问一个英语改错题Mr.Wang taught our maths last year. 1.Ms Lin taught us English last term.的一般疑问句怎么改 .2.My class tacher spoke to my parents yesterday.否定句怎么改3.Leon fell off his bike just now.一般疑问句怎么改4.Uncler tom boughte (a new book).怎么对括号部分提 the teacher taught English last year.(一般疑问句) 唱着《没有共产党就没有新中国》,回顾中国革命历史,你有哪些感想? 学唱《没有共产党就没有新中国》这首歌.结合所学内容和实际,说说你有什么感想? Miss Brown taught our English last term.找出句中的错误并改正. 描写塞外风光的诗句 描写塞外风光的诗句 描写塞外风光的古诗词 描写塞外风光的诗句 描写塞外风景的诗句一定要准确 塞外风光的诗句 英语翻译there is carotid 3-4cm below（deep） in the neck position还有一个问题,就是below和deep这两个词哪个合适 英语美文摘抄不带翻译的 Do you know our English teacher name怎么改错啊 Do you know the girl with whom our English teacher is talking?先行词为什么用whom. Do you know the man ___was talking to our English teacher?A:he B:/ C:whom D:who He is a teacher who (that) taught us English last year.关系代词可以用whom吗 Do you know the teacher whom taught us English last year?This is the house that we visited it two 后面还没完呢，第二句后面加上years ago,要求改这两个句子的错 Miss liu taught us Chinese last year 对Miss liu提问The new schoolbag is on the desk 对on the desk提问My brother went to the zoo last week对last week提问This pen is Jim’s 对 Jim’s提问 ____miss white_____ taught us english last term.对划线部分提问 Miss Lee t__(教)us English. L____,we didn't miss the last bus. 已知数列{an},an属于N*,前n项和Sn=1/8(an+2)^2（1）求证：{an}是等差数列（2）若bn=（1/2）an-30,求数列{bn}的前n项和的最小值 已知数列{an}的前n项和Sn=（（an+1）/2）的平方,当an＞0时,Sn=?