How to Prove the Limit as n Goes to Infinity of a^(1/n) = 1

  • Thread starter Thread starter major_maths
  • Start date Start date
  • Tags Tags
    Limits Proof
major_maths
Messages
30
Reaction score
0

Homework Statement


Let a>1. Prove the limit as n goes to \infty of a1/n = 1.

The Attempt at a Solution


Given \epsilon > 0, \foralln>N, |a1/n-L|<\epsilon and N=(a-1)/\epsilon.
|a1/n-L| = a1/n-1


...and that's where I get confused. I know that I have to multiply (a1/n-1) by something but I'm not sure what exactly (a hint my professor gave).
 
Physics news on Phys.org
Here's a hint that may or may not help. You want |a^(1/n) - 1| < e. So for example, perhaps you want |a^(1/n) - 1| = e/2.
 
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...

Similar threads

Back
Top