Number Theory Questions: Proving p and x2 Congruencies

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SUMMARY

This discussion focuses on proving specific congruencies in number theory, particularly regarding prime divisors and quadratic residues. The first question establishes that prime divisors \( p \) of the integer \( n^2 - n + 1 \) cannot equal 3 and must take the form \( 6k + 1 \). The second question demonstrates that if \( p \equiv 1 \mod 4 \), then the congruence \( x^2 \equiv -1 \mod p \) has a solution, which can be derived using Wilson's Theorem. Participants provided hints and strategies for tackling these proofs.

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  • Understanding of prime numbers and their properties
  • Familiarity with modular arithmetic and congruences
  • Knowledge of Wilson's Theorem in number theory
  • Basic concepts of quadratic residues
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  • Study the implications of prime divisors in polynomial expressions
  • Learn more about quadratic residues and their applications
  • Explore Wilson's Theorem and its proofs in detail
  • Investigate the properties of integers in modular arithmetic
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ak_89
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I have a few questions I am having troubles with. If someone can push me in the right direction that would be awesome. Here are the questions:

1. Prove that the prime divisors, p cannot equal 3, of the integer n2-n+1 have the form 6k+1. (Hint: turn this into a statement about (-3/p) )

2. Show that if p is congruent to 1 (mod 4), then x2 is congruent to -1 (mod p) has a solution given by the least residue (mod p) of ( (p-1)/2)!

I honestly have no idea how to start. I would greatly appreciate some help.
Thanks
 
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For the first question, try multiplying the n2-n+1 term by some integer and rearranging things...

Unfortunately, I'm stumped on how to do the second question :rolleyes:
 
Thanks! I got that proof. But I am still stuck on the second question as well. I played around with it.. but I have yet to get anywhere that is useful to prove the question.

I could really use some help.
 
Hint for #2: Use Wilson's Theorem.

Petek
 

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