已知数列{An}的前N项和Sn=4n2+3n,求证{An}是等差数列
已知数列{An}的前N项和Sn=4n2+3n,求证{An}是等差数列
已知数列{an}的前n项和为Sn=n^2-3n,求证:数列{an}是等差数列
已知数列{an}的前n项和sn=n方+3n,求证数列{an}是等差数列
已知数列{an}的前n项和sn满足sn=an^2+bn,求证{an}是等差数列
.已知数列的前n项之和为Sn=n2+3n,求证{an}为等差数列,若Sn=n2+3n+1呢?
高二超难数列题!已知数列an的前n项和为Sn=n平方-3n 求证数列an是等差数列
高一数学问题:已知数列{An}的前n项和为Sn=n^2+3n,求证:数列{An}是等差数列.
已知数列an其前n项和为Sn,且Sn=3n^2+5n,求证数列an是等差数列
已知等差数列{an}的前n 项和Sn=-3/2n2平方+205n/2,求数列{|an|}前n 项和Tn
已知等差数列{an}的前n项和是Sn=2n2-25n,试求数列{|an|}的前10项的和.
已知数列{An}的各项均为正数,前n项和为Sn,且满足2Sn=An²+n-4 1.求证{An}为等差数列
已知数列{an}的前n项和为Sn,且满足an+2Sn*Sn-1=0,a1=1/2.求证:{1/Sn}是等差数列