Can the Sum of Two Squares Ever Equal 3 Times a Perfect Square?

  • Context: MHB 
  • Thread starter Thread starter MathLover_James
  • Start date Start date
Click For Summary
SUMMARY

The discussion confirms that there are no integers a, b, and c such that the equation a² + b² = 3c² holds true. This conclusion is derived from the sum of two squares theorem, which states that if the prime factorization of an integer includes 3 raised to an odd power, that integer cannot be expressed as the sum of two squares. Since 3c² contains 3 raised to an odd power, it follows that 3c² cannot be represented as the sum of two squares.

PREREQUISITES
  • Understanding of the sum of two squares theorem
  • Basic knowledge of prime factorization
  • Familiarity with integer properties in number theory
  • Concept of odd and even powers in mathematics
NEXT STEPS
  • Research the implications of the sum of two squares theorem in number theory
  • Study prime factorization and its role in integer properties
  • Explore examples of integers that can and cannot be expressed as sums of two squares
  • Investigate related theorems in number theory, such as Fermat's theorem on sums of two squares
USEFUL FOR

Mathematicians, number theorists, and students interested in advanced mathematical concepts related to integer properties and the sum of two squares theorem.

MathLover_James
Messages
1
Reaction score
0
There can't be a, b and c integers such that:

  • a^2 + b^2 = 3*c^2
 
Physics news on Phys.org
That depends on what [math]a, b[/math] and [math]c[/math] are.
 
MathLover_James said:
There can't be a, b and c integers such that:

  • a^2 + b^2 = 3*c^2
This is a consequence of the sum of two squares theorem. This says (among other things) that if the prime decomposition of an integer $n$ contains $3$ raised to an odd power then $n$ cannot be the sum of two squares. Since the number $n = 3c^2$ has an odd power of $3$ in its prime decomposition, the theorem says that it cannot be the sum of two squares.

I don't know whether you can prove the result about $3c^2$ without using the sum of two squares theorem, which is a fairly deep result in number theory.
 

Similar threads

  • · Replies 13 ·
Replies
13
Views
6K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 18 ·
Replies
18
Views
2K
  • · Replies 10 ·
Replies
10
Views
1K
  • · Replies 49 ·
2
Replies
49
Views
5K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 19 ·
Replies
19
Views
3K