Definition (Polynomials)
Let be a field and consider the ring of polynomials over . Explicitly this is the set
Definition (Monic)
We say a polynomial of degree is monic if
Theorem (Degree is closed under addition)
Let be . Then
Theorem (Division of Polynomials)
Let be . We say that divides i.e. if
Definition (Nonzero constant polynomials)
The Nonzero Constant are a class of functions s.t. These are the units of .
Definition (Associate)
Let be polynomials. We say and are associates if is a unit, i.e. is a nonzero constant polynomial.
Definition (Irreducible)
A polynomial is said to be irreducible if is NOT divisible by any where
Theorem (Irreducible factorization)
Every non-constant polynomial is the product of irreducible polynomials.
Theorem (Division Algorithm for Polynomials)
Let be a field and suppose we have with . Then, s.t. with either or and .
Remark
Analogue to Euclidean Algorithm.
Theorem
Given two non-zero elements , the gcd, of and exists and is unique up to units. Moreover, s.t.
Remark
Analogue to Theorem 1.1.
Proposition (If an Irreducible Polynomial divides ab then it divides a or b)
If is an irreducible polynomial and then either or .
Remark
Analogue to If a Prime divides ab it divides one of a or b.
Definition (Relatively prime)
Given two polynomials and , they are said to be relatively prime if their gcd is a unit.