Prove by induction that it follows from Fundamental Theorem of Algebra that every f(x) ∈ C[x]
Prove by induction that it follows from Fundamental Theorem of Algebra that every f(x) ∈ C[x] can be written into a product of linear polynomials in C[x].
According to the Fundamental Theorem of Algebra, every
nonconstant polynomial f (x) ∈
C[x] with complex coefficients has a complex root.
(a) Prove every nonconstant polynomial with complex coefficients
is a product of linear polynomials.
(b) Use the result of the previous exercise to prove every
nonconstant polynomial with real coefficients is a product of
linear and quadratic polynomials with real coefficients.
Bezout’s Theorem and the Fundamental Theorem of Arithmetic
1. Let a, b, c ∈ Z. Prove that c = ma + nb for some m, n ∈ Z if
and only if gcd(a, b)|c.
2. Prove that if c|ab and gcd(a, c) = 1, then c|b.
3. Prove that for all a, b ∈ Z not both zero, gcd(a, b) = 1 if
and only if a and b have no prime factors in common.
1. Prove the Heine-Borel Theorem (Theorem 3.35).
2. Suppose f: X → Y maps from the metric space X to the metric
space Y, and x ∈ X.
Prove that f is continuous at x if and only if, for any sequence
{xn} in X that converges to x, f(xn) → f(x).
2.a Use Rolle's Theorem to prove that if f ′ ( x ) = 0 for all
xin an interval ( a , b ), then f is constant on ( a , b
).
b True or False. The product of two increasing functions is
increasing. Clarify your answer.
c Find the point on the graph of f ( x ) = 4 − x 2 that is
closest to the point ( 0 , 1 ).
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).
Prove using induction:
If F is any field and f(x)=p1(x)p2(x)...pn(x) is a nonconstant
polynomaial of the field, f an element of F, and p1,...,pn are
irreducible factors of the field.
Then, there exists a field L such that f factors into linear
factors over L.
Hint: start with p1(x) to prove that F is a subset of some
K1=F[x]/((p1)) , then induct.