Can the GCD of Polynomials in a Field Always Be Reduced to 1?

In summary, the gcd of two polynomials, p(x) and q(x), can be represented as gcd(p(x),q(x))=p(x)m(x) + q(x)n(x) for some n(x) and m(x) in F[x]. To show that gcd(n(x),m(x))=1 for a fixed gcd(p(x),q(x)), you can let D(x)=gcd(p(x),q(x)) and use the fact that D(x)|q(x) and D(x)|p(x), leading to q(x)=D(x)k(x) and p(x)=D(x)s(x). By substituting these expressions, you get D(x)=D(x)k(x)m(x)+D(x)s(x)n
  • #1
alexfresno
4
0

Homework Statement



We know that the gcd of two polynomials can be written as

gcd(p(x),q(x))=p(x)m(x) + q(x)n(x) for some n(x) and m(x) in F[x] F a fieldI want to show gcd(n(x),m(x))=1 for a fixed gcd(p(x),q(x))

The Attempt at a Solution



Well, what I tried was to let D(x)=gcd(p(x),q(x))
then D(x)|q(x) and D(x)|p(x). Which implies that q(x)=D(x)k(x) and p(x)=D(x)s(x) for some k(x),s(x) in F[x].

Then i got D(x)=D(x)k(x)m(x)+D(x)s(x)n(x) by substitution

Can I divide both sides by D(x) since we are in a Field? If i can...
then won't 1=k(x)m(x)+s(x)n(x) imply gcd(m(x),n(x))=1?? or there is a stronger proof?
 
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  • #2
I think your proof is correct!
 

FAQ: Can the GCD of Polynomials in a Field Always Be Reduced to 1?

What is the GCD of polynomials in a field?

The GCD (Greatest Common Divisor) of polynomials in a field is a polynomial of highest degree that divides evenly into all given polynomials. It is also referred to as the highest common factor.

How is the GCD of polynomials in a field calculated?

The GCD of polynomials in a field can be calculated using the Euclidean algorithm, which involves dividing the polynomials and finding the remainder until a polynomial with a degree of 0 is reached. The last non-zero remainder is the GCD.

What is the significance of the GCD of polynomials in a field?

The GCD of polynomials in a field is important because it allows for simplification and factorization of polynomials. It also helps in solving polynomial equations and finding common factors.

Can the GCD of polynomials in a field be equal to 1?

Yes, the GCD of polynomials in a field can be equal to 1 if the given polynomials have no common factors. This means that the polynomials are relatively prime.

Can the GCD of polynomials in a field be negative?

No, the GCD of polynomials in a field is always a positive polynomial. This is because the GCD is defined as the highest common factor, and by definition, a factor cannot be negative.

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