已知:loga1(b1)=loga2(b2)=……logan(bn)=x,则log(a1a2……an)(b1b2……bn
已知a1,a2,…,an;b1,b2,…,bn(n是正整数),令L1=b1+b2+…+bn,L2=b2+b3+…+bn,
an=2^n bn=2n Tm=b1/a1+b2/a2+……+bn/an,求Tn
己知an是等差数列 a2+a4=6 a5=5 {bn}满足bn=anan+1则1/b1+1/b2+……+1/bn等于
已知数列{An}与{Bn}都是公差不为零的等差数列,且limAn/Bn=3,求lim(B1+B2+……+B2n)/(n*
已知数列{an}、{bn}都是公差不为零的等差数列,且liman/bn=3,求lim(b1+b2+……b3n)/(n*a
令bn=1/(n2+2n) Tn=b1+b2+b3+……+bn
在数列{an},{bn}中,a1=2,b1=4,……证明:1/(a1+b1)+1/(a2+b2)+…1/(an+bn)<
有两个等差数列{an},{bn},满足a1+a2+…+an/(b1+b2+…+bn)=5n/(3n+6),则a7/b7=
己知an是等差数列 a2+a4=6 a5=5 {bn}满足bn=an(an+1)则1/b1+1/b2+……+1/bn等于
有两个等差数列{an],{bn]满足(a1+a2+a3+…an)/(b1+b2+b3+…bn)=(7n+2)/(n+3)
等差数列{an}中a2=8,S6=66.设bn=2/[(n+1)an],Tn=b1+b2+…+bn,
已知an=2n-1,an=b1/2+b2/2^2+b3/2^3+……+bn/2^n,求数列bn的前n项和Sn