神马作文网数列方面的（如图）
来源：学生作业帮 编辑：神马作文网作业帮 分类：数学作业 时间：2024/11/13 23:10:45
数列方面的（如图）
2a(n+2)= 3a(n+1) + (3/2)^(n+1)
2^(n+2)a(n+2) - 3.2^(n+1) a(n+1) = 3^(n+1)
(2/3)^(n+2)a(n+2) - (2/3)^(n+1)a(n+1) = 1/3
a(n+2)/(3/2)^(n+2) - a(n+1)/(3/2)^(n+1) = 1/3
=>{an/(3/2)^n}是等差数列,d=1/3
an/(3/2)^n - a2/(3/2)^2 = (n-2)/3
an/(3/2)^n - 8/9 = (n-2)/3
an/(3/2)^n = (3n+2)/9
an = [(3n+2)/9] (3/2)^n
ie
an =1 ; n=1
= [(3n+2)/9] (3/2)^n ; n=2,3,4,...
2^(n+2)a(n+2) - 3.2^(n+1) a(n+1) = 3^(n+1)
(2/3)^(n+2)a(n+2) - (2/3)^(n+1)a(n+1) = 1/3
a(n+2)/(3/2)^(n+2) - a(n+1)/(3/2)^(n+1) = 1/3
=>{an/(3/2)^n}是等差数列,d=1/3
an/(3/2)^n - a2/(3/2)^2 = (n-2)/3
an/(3/2)^n - 8/9 = (n-2)/3
an/(3/2)^n = (3n+2)/9
an = [(3n+2)/9] (3/2)^n
ie
an =1 ; n=1
= [(3n+2)/9] (3/2)^n ; n=2,3,4,...