(2012•安徽模拟)设等比数列{an}的前n项和为Sn. 若a1=1,S6=4S3,则a4=( )
设等比数列{an}的前n项和为Sn,若S6:S3=1:2,则S9:S3=?
设等比数列an的前n项的和为Sn,若S6/S3=3,则S9/S6=
1.设等比数列{an}的前n项和为Sn,若S6/S3=3,则S9/S6=?
(2014•南宁二模)设等比数列{an}的前n项和为Sn,若a1=1,S6=4S3,则a10=______.
设sn是等比数列{an}的前n项和,是s3/s6=1/3.则s6/s12=
设等比数列an的前n项的和为Sn,若S6/S3=1/2,则S9/S3=
设Sn为等比数列{an}的前n项和,若a1=1,且2a2,S3,a4+2成等差数列,则数列{an2}的前5项和( )
设Sn是等差数列An的前n项和,若S3/S6=1/3,则S6/S12等于
设数列{an}的前n项和为Sn,若a1=1,an+1=3Sn(n∈N*),则S6=( )
设Sn是等比数列{an}的前n项和,S3,S9,S6成等差数列,且a2+a5=2am,则m等于( )
已知正项等比数列{an}的前n项和为Sn,若S3=3,S9-S6=12,则S6=______.
设{an}是公比不等于1的等比数列,Sn是其前n项和,若a1,2a7,3a4成等差数列,求证12S3,S6,S12-S6