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Units in a ring

  • Thread starter juniormint
  • Start date
  • #1

Homework Statement


In the ring Z([tex]\sqrt{}5i[/tex]) = n + m[tex]\sqrt{}5i[/tex], n and m integers, find the units.


Homework Equations



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The Attempt at a Solution


I know 1 and -1 are units, and my textbook seems to indicate that [tex]\sqrt{}5i[/tex] and -[tex]\sqrt{}5i[/tex] are also units, but I don't know if that's right because I don't know what the inverse of those elements would be -- multiplying them together gives you 5, right? Are there different units I haven't found?

thanks!
 

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