题目内容
试题答案
设数列{an}前n项和为sn,且(3-m)Sn+2man=m+3(n∈N*),其中m为常数,m≠-3.
(1)求证:{an}是等比数列;
(2)若数列{an}的公比q=f(m),数列{bn}满足b1=a1,bn=f(bn-1)(n∈N*,n≥2),证明为等差数列,并求bn
设等比数列{an}前n项的和为Sn,且4a1,2a2,a3成等差数列,若a1=1,则S4=
A.7
B.8
C.15
D.16