S
由等比数列的求和公式和通项公式可得:
S4 a3=
a1(1-24) 1-2 a1•22= 15a1 4a1= 15 4 故答案为: 15 4
设等比数列 {an} 的公比为q,前n项和为Sn,若S(n+1),Sn,S(n+2)成等差数列,则q=
设等比数列{an}的公比q=2,前n项的和为Sn,则S
设等比数列{an}的公比q=2,前n项和为Sn,S4\a2
设等比数列{an}的公比为q,前n项和为Sn,若Sn+1,Sn,Sn+2成等差数列,则公比q为( )
设等比数列{an}的公比为q,前n项和为Sn,若Sn+1,Sn,Sn+2成等差数列,则q=?
设等比数列an的公比为q=1/2,前n项和为Sn,则S4/a4=?
设等比数列an的公比为q,前n项和为sn,若s(n+1),sn,s(n+2)成等差数列,求q的值
设等比数列an的公比q=2,前n项和为Sn,则S4/a4=
设等比数列{an}的公比q=2,前n项和为Sn,则S4/a2=?
设等比数列an的公比q=2,前n项和为sn,则s4\a2=
设等比数列an的公比q=2,前n项和为sn,则s4除以a2=
设等比数列{an}的公比q=1/2,前n项和为Sn,则S4/a4=
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