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Homework Help: Groups math help

  1. Apr 18, 2013 #1
    Show that a•b=(a+b)^2 has no identity for real numbers
    Hi this is a new topic please help
  2. jcsd
  3. Apr 18, 2013 #2


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    Science Advisor

    An "identity" for an operation would be a member of the group, I, such at a•I= I•a= a. So you just need to show there is no number, I, such that (a+ I)^2= a for every a.
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