已知数列{an}满足a1,a(n+1)=2an +1则它的通项公式是_________.

a1=1
2025-06-21 08:17:06
推荐回答(2个)
回答1:

a(n+1)=2an +1
a(n+1)+1=2(an +1)
[a(n+1)+1]/(an +1)=2
数列{an+1}是等比数列,首项为2;公比为2
an+1=2*2^(n-1)=2^n
an=2^n-1

回答2:

a(n+1)=2an +1
a(n+1)+1=2an +1+1
a(n+1)+1=2(an +1)
[a(n+1)+1]/(an +1)=2
所以数列{an+1}是等比数列,首项为(a1 +1),公比为2
an+1=(a1+1)*2^(n-1)
通é