Compute the G.C.D of two Gaussian Integers

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SUMMARY

The greatest common divisor (G.C.D) of the Gaussian integers a = 14 + 2i and b = 21 + 26i is determined by examining the norms of both integers. The norms are calculated as norm(14 + 2i) = 200 and norm(21 + 26i) = 1117. Since 200 and 1117 are co-prime, their G.C.D is 1, indicating that the G.C.D of a and b is a unit in the Gaussian integers, specifically one of the units (1, -1, i, -i) in the ring of Gaussian integers.

PREREQUISITES
  • Understanding of Gaussian integers and their properties
  • Familiarity with the concept of norms in complex numbers
  • Knowledge of co-primality and greatest common divisors
  • Basic algebra involving complex numbers
NEXT STEPS
  • Study the properties of Gaussian integers in detail
  • Learn how to compute norms of complex numbers
  • Explore the concept of units in rings, specifically in Gaussian integers
  • Investigate algorithms for finding G.C.D in various number systems
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Students studying abstract algebra, mathematicians interested in number theory, and anyone looking to deepen their understanding of Gaussian integers and their applications.

DeldotB
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Homework Statement


Hello all I apologize for the triviality of this:
Im new to this stuff (its easy but unfamiliar) I was wondering if someone could verify this:

Find the G.C.D of a= 14+2i and b=21+26i.

a,b \in \mathbb{Z} [ i ] - Gaussian Integers

Homework Equations



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The Attempt at a Solution



Well, is it true that any common divisor must also divide the G.C.D of the norm's of aandb?

If so then, norm(14+2i)=200
norm(21+26i)=1117

Well, since 1117 and 200 are co-prime, their greatest common divisor is one. Thus,

Thus the G.C.D of a,b is a unit (1,-1,i,-i) in the ring.

Thanks
 
Last edited:
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Everything that divides (a+bi) also divides (a+bi)(a-bi), sure.
DeldotB said:
Well, since 1117 and 200 are co-prime
In the integers. You'll have to show that this is true for Gaussian integer factors as well.
 
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