Proving Existence of Limit of Sequence {xn}

cristina89
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Be {xn} a sequence that satisfies the condition 0 ≤ x_{m+n} ≤ x_{m} + x_{n}. Prove that lim_{n ->∞} xn/n exists.

I'm kind of lost in this.
 
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cristina89 said:
Be {xn} a sequence that satisfies the condition 0 ≤ x_{m+n} ≤ x_{m} + x_{n}. Prove that lim_{n ->∞} xn/n exists.

I'm kind of lost in this.

I would start by thinking like this:

x2<=x1+x1

x3<=x2+x1<=x1+x1+x1

etc. What can you make of that?
 
Ughh I'm still lost :S
 
Hi cristina89! :smile:

Can you write xn in the form that Dick suggested?
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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