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Converging to a limit

  1. Apr 8, 2004 #1
    How do you prove that the lim n->infinity (n-1/n)=1?

    I know that the definition of convergence for a sequence xn is for all E>0, there exists an N is an element of the set of a natural numbers and there exists a n>=N, such that lxn-Ll<E.

    Is it sufficient to just show that 1 is the least upper bound, and that

    1- (n-1/n) <E and thus 1-E<(n-1/n) and then n-nE<n-1 and ultimately there is an n such that n-nE+1<n
     
  2. jcsd
  3. Apr 8, 2004 #2

    HallsofIvy

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    I am tempted to say "you don't- it's not true!". But you mean (n+1)/n NOT
    "n+(1/n)" which is how "n+ 1/n" would normally be interpreted.

    (n+1)/n= 1+ 1/n . It should be easy for you to prove that 1/n-> 0 as n-> infinity.

    Yes, you can do it as |1- (n-1)/n|= |(n-n+1)/n|= 1/n< E- that's much simpler than
    multiplying by the denominator,n, before simplifying.
     
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