66. Let R be a commutative ring with identity. An ideal I of R is irreducible if it cannot be expressed as the intersection of two ideals of R neither of which is contained in the other. the following. (a) If P is a prime ideal then P is irreducible. (b) If z is a non-zero element of R, then there is an ideal I, maximal with respect to the property that r gI, and I is irreducible. (c) If...
Q 5. Let F be a field and consider the polynomial ring l (a) State the Division Algorithm for polynomials in Plrl. b) Let a e F. Prove that -a divides f(x) in Fix] if and only if (a)- (c) Prove that z-37 divides 42-1 in F43[z].
Q 5. Let F be a field and consider the polynomial ring l (a) State the Division Algorithm for polynomials in Plrl. b) Let a e F. Prove that -a divides f(x) in...
Let R be an ED but not a field, with a norm function N R-Z U0 such that N(ab for all a, bE R. (a) Prove that N(1R) (b) If r E R is a unit, show that N(r) 1. (c) If r E R is nonzero, show that N(r) 0. (d) For any r E R, prove that if N(r) 1, then r is a unit N(a)N(b) e) For any r e R if N() is a prime mumber,...
Let R be a commutative ring with 1. Prove that Ris a field if and only if the only ideals in Rare (0) and R.
Rings and fields- Abstract Algebra
2. (a) (6 points) Let f (x) be an n over a field F. Let irreducible polynomial of degree g() e Fx be any polynomial. Show that every irreducible factor of f(g()) E Flx] has degree divisible by n (b) (4 points) Prove that Q(2) is not a subfield of any cyclotomic field over Q.
2. (a) (6 points) Let f (x) be an n over a field F. Let irreducible polynomial of degree g()...
4. Let F be a field. Prove that for all polynonials f(x), g(x), h (z) є FI2], if f(x) divides g(x) and f(z) divides h(r), then for all polynomials s(r),t() E Fr, f() divides s()g(r) +t(x)h(r).
4. Let F be a field. Prove that for all polynonials f(x), g(x), h (z) є FI2], if f(x) divides g(x) and f(z) divides h(r), then for all polynomials s(r),t() E Fr, f() divides s()g(r) +t(x)h(r).
3. Let f, g : a, bl → R be functions such that f is integrable, g is continuous. and g(x) >0 for al x E [a, b]. Since both f,g are bounded, let K> 0 be such that f(x)| 〈 K and g(x)-K for all x E la,b] (a) Let η 〉 0 be given. Prove that there is a partition P of a,b] such that for all i (b) Let P be a partition as in (a). Prove...
6. Let R be a ring, and let 11 and 12 be ideals of R. We define the product of 11 and 12 to be 1112 = {TER:r => aibi, with k > 1, Q1, ..., ak € 11, b1,..., bk € 12 In other words, an element of the product 1.12 is a finite sum of products a;bi, where a, comes from I and bi comes from 12. (a) Prove that 11 12 is an ideal of R, contained...
(8) Let E C R" and G C R" be open. Suppose that f E G and g G R', so that h = go f : E → R. Prove that if f is differentiable at a point x E E, and if g is differentiable at f (x) E G, then the partial derivatives Dihj(x) exist, for all and j - ...., and 7m に! (The subscripts hi. g. fk denote the coordinates of the functions h, g....
3. Let f, g : [a,b] → R be functions such that f is integrable, g is continuous, and g(x) >0 for all r E [a, b] Since both f,g are bounded, let K >0 be such that lf(z)| K and g(x) K for all x E [a3] (a) Let n > 0 be given. Prove that there is a partition P of [a, b such that U (P. f) _ L(P./) < η and Mi(P4)-mi(P4) < η for all...