Question

已知递推公式(2n+1)an+1=(3n+1)an,求an的通项公式。谢谢啦，数学大神

额，不好意思，等式左边是an+1,n+1是脚标

Answer 1

[(3n+1)－(2n+1)]an＝1
nan＝1
an＝1／n

Answer 2

(2n+1)an+1=(3n+1)an,
展开：2n*an+an+1=3n*an+an
得：n*an=1
所以，an=1/n

Answer 3

2nan+an+1=3nan+an，nan=1，an=1/n