Question

证明数列是等差数列已知：数列{an}的Sn=nan(n是正整数),证明{an}是等差数列.

Answer 1

An+1=Sn+1 - Sn=(n+1)*An+1 - n*An

=>n*An+1=n*An

=>An+1=An

因此,An为等差数列.