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Homework Help: An unusually easy proof of vector.

  1. Sep 18, 2011 #1
    1. The problem statement, all variables and given/known data
    See the attachment.


    2. Relevant equations



    3. The attempt at a solution

    It seems this proof is trivial, too easy that I am not sure if I do it correctly.
     

    Attached Files:

  2. jcsd
  3. Sep 18, 2011 #2

    HallsofIvy

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    Science Advisor

    Yes, it is too trivial

    You start by saying [itex]||u||_\infty= |u_n|[/itex]. You can't do that [itex]||u||_\infty[/itex] is the largest component, not necessarily the nth component

    You can say [itex]||u||_\infty\le |u_n|[/itex]. Does that help?
     
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