等比数列an的前n项和为Sn,且4a1,2a2,a3成等差数列.若a1等于1,则S4为多少?
等比数列an的前n项和为Sn,且4a1,2a2,a3成等差数列.若a1等于1,则S4为多少?
等比数列{an}的前n项和为Sn,且4a1,2a2,a3成等差数列.若a1=1,则S4=( )
等比数列{an}的前n项和为Sn,且4a1,2a3,a3成等差数列,若a1=1,则S4=?
等比数列{an}的前n项的和为Sn.若4a1.2a2.a3成等差数列,则S4/a4的值是?
已知sn是公差不为0的等差数列{an}的前n项和,且s1,s2,s4成等比数列,则a1分之a2+a3
设Sn是公差不为0的等差数列an地前n项和且S1,S2,S4成等比数列,则a1/a2等于
1.已知等差数列{an}的前n项和为Sn,若S3=12,且2a1,a2,a3+1成等比数列求 Sn
20、已知正向等差数列{an}的前n项和为Sn,若S3=12,且2a1,a2,a3+1成等比数列.
已知正向等差数列{an}的前n项和为Sn,若S3=12,且2a1,a2,a3+1成等比数列.
等比数列的前n项和为Sn,a1为3/2,且S3,S5,S4成等差数列,求an
等差数列{an}的前n项和为Sn,设S3=12,且2a1,a2,a3 1成等比数列,求Sn?
等差数列an的前n项和为Sn,设S3=122,且2a1.a2.,a3+1成等比数列,求Sn