Question

已知数列{an}满足a1=2/3,an+1=n/n+1*an,求an大家帮我解哈！谢谢哈！过程写详细点！

Answer 1

a(n+1)=n/(n+1)*an
(n+1)*a(n+1)=nan
(n+1)a(n+1)/nan=1
∴{nan}是公比为1的等比数列
首项为2/3，通项nan=2/3
∴an=2/3n

Answer 2

an+1=n/n+1*an所以(n+1)a(n+1)=n*an即bn=nan为一常数列且值为2/3
an=2/(3n)