Question

在数列{an}中,a1=1/3,An+1=An+2/3，请写出数列的前5项，并判断是不是等差数列

求过程~

Answer 1

A1=1/3,A2=A1+2/3=1,A3=A2+2/3=5/3,A4=A3+2/3=7/3,A5=A4+2/3=3
A(n+1)-An=2/3为一定值,故是等差数列.

Answer 2

a1=1/3
a2=1
a3=5/3
a4=7/3
a5=9/3=3
是等差数列。