Sn是等比数列{an}的前n项和,a1=,9S3=S6,设Tn=a1a2a3…an,则使Tn取最小值的n值为(...
问题详情:Sn是等比数列{an}的前n项和,a1=,9S3=S6,设Tn=a1a2a3…an,则使Tn取最小值的n值为().A.3 B.4 C.5 D.6【回答】C【解析】设等比数列的公比为q,故由9S3=S6,得9×,解得q...
问题详情:Sn是等比数列{an}的前n项和,a1=,9S3=S6,设Tn=a1a2a3…an,则使Tn取最小值的n值为().A.3 B.4 C.5 D.6【回答】C【解析】设等比数列的公比为q,故由9S3=S6,得9×,解得q...
问题详情:已知{an}是首项为1的等比数列,Sn是{an}的前n项和,且9S3=S6,则数列的前5项和为()A.或5 B.或5C. D.【回答】...