We’ll say a polynomial f(x) ∈ R[x] is prime if the ideal (f(x))
⊂ R[x] is...
We’ll say a polynomial f(x) ∈ R[x] is prime if the ideal (f(x))
⊂ R[x] is prime. If F is a field with finitely many elements (e.g.,
Z/pZ), prove that f(x) ∈F [x] is prime if and only if it’s
irreducible.
f:
R[x] to R is the map defined as f(p(x))=p(2) for any polynomial
p(x) in R[x]. show that f is
1) a homomorphism
2) Ker(f)=(x-2)R[x]
3) prove that R[x]/Ker(f) is an isomorphism with R.
(R in this case is the Reals so
R[x]=a0+a1x+a1x^2...anx^n)
Prove the following:
Let f(x) be a polynomial in R[x] of positive degree n.
1. The polynomial f(x) factors in R[x] as the product of
polynomials of degree
1 or 2.
2. The polynomial f(x) has n roots in C (counting multiplicity).
In particular,
there are non-negative integers r and s satisfying r+2s = n such
that
f(x) has r real roots and s pairs of non-real conjugate complex
numbers as
roots.
3. The polynomial f(x) factors in C[x] as...
Let R be a commutative domain, and let I be a prime ideal of
R.
(i) Show that S defined as R \ I (the complement of I in R) is
multiplicatively closed.
(ii) By (i), we can construct the ring R1 =
S-1R, as in the course. Let D = R / I. Show that
the ideal of R1 generated by I, that is,
IR1, is maximal, and R1 / I1R is
isomorphic to the
field of fractions of...
Use induction to prove
Let f(x) be a polynomial of degree n in Pn(R). Prove that for
any g(x)∈Pn(R) there exist scalars c0, c1, ...., cn such that
g(x)=c0f(x)+c1f′(x)+c2f′′(x)+⋯+cnf(n)(x), where f(n)(x)denotes the
nth derivative of f(x).
Given n ∈N and p prime number and consider the polynomial f (x) = xn (xn-2)+1-p
1)Prove that f (x) is irreducible in Q [x]
2) If n = 1 and p = 3, find Q [x] / f (x))
3) Show that indeed Q [x] / (f (x)) is a field in the previous paragraph
PLEASE answer all subsections
f(x) = x ln x
(a) Write the Taylor polynomial T3(x) for f(x) at center a =
1.
(b) Use Taylor’s inequality to give an upper bound for |R3| =
|f(x) − T3(x)| for |x − 1| ≤ 0.1. You don’t need to simplify the
number.
5. (a) Let f : R \ {−1} → R, f(x) = x+1. Show that f is
injective, but not surjective.
(b) Suppose g : R\{−1} → R\{a} is a function such that g(x) =
x−1, where a ∈ R. Determine x+1
a, show that g is bijective and determine its inverse
function.