若等差数列{an}满足an×an+1=n²+3n+2,则公差为1,还是±1?求详解,
若等差数列{an}满足an×an+1=n²+3n+2,则公差为1,还是±1?求详解,
等差数列an中,公差d=1/2,an=3/2,sn=-15/2,则n等于 详解!
等差数列{an}中,an=3n-1,则公差d为
An为等差数列,且满足A(n+1)=An²-nAn+1,n=1,2,3……求An的通项公式
已知等差数列{an}满足a(n+1)=an+3n+2,且a1=2,求an.
已知公差不为0的等差数列{An}的首项A1=1,前n项和为Sn,若数列{Sn/An}是等差数列,求An?
已知等差数列{an}的公差d>0,满足a3a9=27,a5+a7=12 答案(1)an=n (2)Sn=n/n+1 (3
an是首项为3,公差,公差为2的等差数列,则lim(1/a1a2+1/a2a3+……+1/a(n-1)an)=
,(苏2004)设无穷等差数列{an}的前n项和为sn.(Ⅰ)若首项a1=3/2,公差d=1,求满足 的
等差数列{an},{bn}的前n项和分别为An,Bn,切An/Bn=2n/3n+1,求lim(n→∞)an/bn
已知等差数列{an}中,a1=3,前n项和Sn=1/2(n+1)(an+1)-1,求数列{an}的公差.
设数列{an}的首项a1=1,且{a(n+1)-an}是首项为3,公差为2的等差数列,求{an}