Polynomials Flashcards
What is a polynomial
Polynomial is a0+ A1x+…+ AnX^n
What is degree of 0 polynomial
Degree of 0 polynomial is - inf
When is a polynomial Monic
Polynomial is monic when leading coefficient = 1 Xn
What is a ring
A ring is where there is commutative addition and scalar multiplication and have 1 and 0
What are degrees of polynomials in a ring
Degrees of polynomials in a ring are:
Det pq = det p + deg q
Deg(p+q) <= max(deg p, deg q)
What is evaluation of polynomial p = a0+ …+ AnX^n
Evaluation of polynomial p= a0 +…cAnX^n is
P(t) = A0 + A12 +…+Ant^n
What does evaluation preserve
Evaluation preserves addition and multiplication, (p+q)(t) = p(t) + q(t) (pq)(t) = p(t)q(t) so p to p(t) is a linear map
Defined function
If p,q are in F([x], then how can p be written
If p,q F[x] then p can be written as
P= s*q + r with unique r,s in F[x] and deg r < deg q
What is fundamental theorem of algebra
Fundamental theorem of algebra is every polynomial has a root in C, polynomial of deg n has at most n roots
How can polynomials be written in C
In C, polynomials can be written as p = a*PI(x - Li)^ni
A is leading coefficient, Ali are roots, n is multiplication