Question

CAUCHY: let Xn C R be a sequence s.t. |xn+1-xn| < r^n where 0 11 years ago

Answer 1

here is a nice answer written out more easily and clearly than i could write it here
go through it and see if you understand the steps
it makes use of geometric series and a simple triangle inequality
if you have questions after repost
http://math.stackexchange.com/questions/378062/please-help-prove-that-x-n-is-a-cauchy-sequence-if-x-n1-x-n-leq-cr

Answer 2

I think I understand... is there any like trick or something this is going by?