高二 等差数列已知数列{an},其中a1=a,a2=b.记bn=an+1 -an,如果｛bn}是公差为d的等差数列,则a

（高二数学）已知数列{an}是首项a1=a,公差为2的等差数列;数列{bn}满足2bn=(n+1)an 已知数列{an}中,a1=5/6,a2=19/36,且数列｛bn}是公差为-1的等差数列,其中b1＝Log2 [a(n+ 【紧急--高一数学】已知数列{an}是首项a1=a,公差为2的等差数列;数列{bn}满足2bn=(n+1)an 已知等差数列{an}中,a1=a,公差d=1,若bn=an^2-a(n-1)^2,试判断数列{bn}是否为等差数列 已知等差数列{an},a1=a,公差d=1.若bn=an^2-a(n+1)^2,试判断数列{bn}是否为等差数列.并证明 已知等差数列首项是a1,公差是d,bn=3an+4b,则数列是否为等差数列 已知数列{an}是首项a1=a,公差为2的等差数列,数列{bn}满足2bn=（n+1）an 1.已知数列｛an｝是首项a1=a,公差为2的等差数列;数列｛bn｝满足2bn=(n+1)an. 已知数列{An}与{Bn}都是公差不为零的等差数列,且limAn/Bn=2,求lim(A1+A2+……+An)/(n*B 已知{an}是公差为d的等差数列,bn=1/n(a1+a2+……an),数列{an}、{bn}的前n项和分别是Sn、Tn 已知数列{an}是等差数列,且bn=an+a(n-1),求证bn也是等差数列 已知数列{An}的前n项和为Sn,A1=A2=1,bn=nSn+（n+2)An,数列{bn}是公差为d的等差数列,