f(n)=1+1/2+1/3+1/4+…………+1/(3n-1),求f(n)-f(n-1)
问题描述:
f(n)=1+1/2+1/3+1/4+…………+1/(3n-1),求f(n)-f(n-1)
要详细过程
有追加
答
f(n-1)=1+1/2+1/3.+1/(3n-4)
f(n)-f(n-1)=1/(3n-1)+1/(3n-2)+1/(3n-3)