等差数列{an}的公差为d(d≠0),它的前n项的和为Sn;等比数列{bn}的公比为q(q的绝对值>1),它的前n项和为Bn求lim(Sn、n*an-Bn/bn)lim(Sn/(n*an)-Bn/bn)

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等差数列{an}的公差为d(d≠0),它的前n项的和为Sn;等比数列{bn}的公比为q(q的绝对值>1),它的前n项和为Bn求lim(Sn、n*an-Bn/bn)lim(Sn/(n*an)-Bn/bn)

等差数列{an}的公差为d(d≠0),它的前n项的和为Sn;等比数列{bn}的公比为q(q的绝对值>1),它的前n项和为Bn求lim(Sn、n*an-Bn/bn)lim(Sn/(n*an)-Bn/bn)
等差数列{an}的公差为d(d≠0),它的前n项的和为Sn;等比数列{bn}的公比为q(q的绝对值>1),它的前n项和为Bn
求lim(Sn、n*an-Bn/bn)
lim(Sn/(n*an)-Bn/bn)

等差数列{an}的公差为d(d≠0),它的前n项的和为Sn;等比数列{bn}的公比为q(q的绝对值>1),它的前n项和为Bn求lim(Sn、n*an-Bn/bn)lim(Sn/(n*an)-Bn/bn)
用等差和等比前n项和公式把Sn和Bn代换后化简后:
=lim(2a1+(n-1)d)/(2a1+2(n-1)d)—lim(1-q^n)/(q^n-1(1-q))
=1/2-1
=-1/2

lim()里面什么,看不懂


根据题意得Sn=na1+n(n-1)d/2,Bn=b1[1-q^(n-1)]/(1-q),
an=a1+(n-1)d,bn=b1q^(n-1)
所以lim(Sn/(n*an)-Bn/bn)=lim{[na1+n(n-1)d/2]/n[a1+(n-1)d]-[b1(1-q^(n-1))/(1-q)]/b1q^(n-1)}
=1/2-(-1)=3/2

你写的啥么,根本看不懂