已知(an)为等差数列 求证(bn)=3n+2为等差数列
已知数列an是等差数列 且bn=2^a{n}求证bn为等比数列 {}里为下标 ^为上标
已知等比数列{an},首项为81,数列{bn}满足bn=㏒3an,其前n项和为Sn,求证﹛bn﹜为等差数列.
已知{an}是等差数列,bn=kan+m(k,m为常数).求证{bn}是等差数列
已知数列an的前n项和为sn=5/6n(n+3),1:求证an为等差数列 2:设bn=a3n+a
已知{an},{bn}均为等差数列,前n项的和为An,Bn,且An/Bn=2n/(3n+1),求a10/b10的值
已知数列{an}满足a1+a/4,(1-an)a(n+1)=1/4,令bn+an-1/2 求证数列{1/bn}为等差数列
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是等差数列,且bn=an+a(n+1).求证数列bn是等差数列.
已知数列{An}是等差数列,且Bn=An+A(n+1).求证数列{Bn}是等差数列
已知等差数列{ an}的前几项和为Sn,a1=1+根号2 S3=9+3根号2 设 bn=Sn/n(n属于正整数 ) 求证
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}
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