设Bn=A1+A2+...+An/n,若{an}等差数列,且公差为d,问{Bn}是否为等差数列
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
设等差数列{an}的公差d≠0,数列{bn}为等比数列,若a1=b1,b2=a3 b3=a2,则bn的公比为
等差数列an中,a1=a,公差d=1,bn=an^2-a(n+1)^2,判断bn是否为等差数列
已知{an}{bn}都是公差不为0的等差数列.且lim(n趋近无穷)an/bn=2.求lim(n趋近无穷)(a1+a2+
等差数列{an}的公差为-2,且a1,a3,a4成等比数列.设bn=2/n(12-an)(n∈N*),求数列{bn}的前
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
已知等差数列{an}前n项和为Sn,公差d≠0,且S3+S5=50,a1,a4,a13,成等比数列 设{bn/an}是首
设数列an前n项和Sn已知a1=a2=1 bn=nSn+(n+2)an数列bn公差为d的等差数列n属于N...
bn}是首项为1,公差4/3的等差数列,且bn=(a1+2a2+……+nan)/(1+2+……+n), 1.求证{an}
已知an为等差数列,且a2=-8,若等差数列bn满足b1=-8,b2=a1+a2+a3,求bn的前n项和Tn.
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