试题与答案

若数列{an}是等差数列,且bn=a1+a2+…+ann,则数列{bn}是等差数

题型:填空题

题目:

若数列{an}是等差数列,且bn=
a1+a2+…+an
n
,则数列{bn}是等差数列.类比上述性质,相应地,若数列{cn}是等比数列,且cn>0,dn=______,则有数列{dn}也是等比数列.

答案:

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