Convergence of Sequence Summation and Limit Prove

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
2 replies · 2K views
l888l888l888
Messages
49
Reaction score
0

Homework Statement


let (An) be a sequence in R with |summation from n=1 to infinity(An)|< infinity. Prove lim as n goes to infinity of ((A1 +2A2+...+nAn)/n) = 0


Homework Equations





The Attempt at a Solution


I think |summation from n=1 to infinity(An)|< infinity means the summation converges .I rewrote " lim as n goes to infinity of ((A1 +2A2+...+nAn)/n) = 0 " as "lim as n goes to infinity of ((summation from k=1 to n of nAn)/n)=0. Since I assmumed "summation from n=1 to infinity(An)" converges, that would imply the lim of An is 0. I don't know how to use this info to prove what i need to prove. Hope you can understand this. I don't know how to use tek.
 
Physics news on Phys.org
Hint: If the summation of An converges and for all n ,Bn<An, then the summation of Bn converges.
 
Forgive my missing absolute. |Bn|<|An|