Explore BrainMass
Share

# Ring Theory

### Find a commutative ring R with no ideal

Find a commutative ring R with no ideal other than (0) and R that is not a Field.

### Maximal Ideals, Cosets, Polynomials and Quotient Rings

Consider the ring of Z[x] and its ideal (2, ) Find the size of Z[x] / (2, ) and find a coset representative for each coset of Z[x] / (2, ) ; Is the Z[x] / (2, ) a field (You need to prove it) ? Is the Z[x] / (2, ) an integral domain (You need to prove it)

### Polynomial Rings : Relatively Prime Elements

Let F, K be two fields, F is a subset of K and suppose f(x), g(x) &#1028; F[x] are relatively prime in F[x]. Prove that they are relatively prime in K[x].

### Ring Theory : Prove that the additive inverse of a unit is a unit.

This question is of concept of Ring. Prove that the additive inverse of a unit is a unit.

### Prove or disprove the existence of non-commutative division ring of order 4.

Prove or disprove the existence of non-commutative division ring of order 4.

### Ring & Field Theory : Associative and Distributive Properties of Multiplication

Let F be the set of all functions f : R&#61664;R. We know that <F, +> is an abelian group under the usual function addition, (f + g)(x) = f(x) + g(x). We define multiplication on F by (fg)(x) = f(x)g(x). That is, fg is the function whose value at x is f(x)g(x). Show that the multiplication defined on the set F satisfies axio

### Ring Theory: Greatest Common Divisor (GCD)

Please respond to the following question: Find the greatest common divisor of the following polynomials over F, the field of rational numbers: x^3 - 6x^2 + x + 4 and x^5 - 6x + 1

### Ring Theory: Determining the Greatest Common Divisor (GCD)

If f(x) = x^5 + 2x^3 + x^2 + 2x + 3, g(x) = x^4 + x^3 + 4x^2 + 3x + 3, then find greatest common divisor of f(x) and g(x) over the field of residue classes modulo 5 and express it in the form d(x) = m(x) f(x) + n(x) g(x) where d(x) = g.c.d. of f(x) and g(x).

### Ring Theory : Euclidean Rings and GCD

If the least common multiple of a and b in the Euclidean ring R is denoted by [a,b], prove that [a,b] = ab/(a, b) where (a, b) is the greatest common divisor of a and b.

### Euclidean Rings and Elements with Least Common Multiples

Given two elements a, b in the Euclidean ring R their least common multiple c&#1028;R is an element in R such that a&#9474;c and b&#9474;c and such that whenever a&#9474;x and b&#9474;x for x&#1028;R then c&#9474;x. Prove that any two elements in the Euclidean ring R have a least common multiple in R.

### Ring Theory : commutative ring with a unit element form abelian

Prove that the units in a commutative ring with a unit element form an abelian group.

### Associate of a Greatest Common Divisor and Euclidean Rings

In a Euclidean ring R, any associate of a greatest common divisor is a greatest common divisor. keywords: GCD, GCDs

### Ring Theory : Euclidean Rings

Prove that in a Euclidean ring ( a , b ) can be found as follows b = q0 a + r1 where d ( r1) < d (a ) a = q1 r1 + r2 where d ( r2) < d (r1 ) r1 = q1 r1 + r2 where d ( r3) < d ( r2 )

### Ring Theory : Direct Products, Mappings and Homomorphisms

Let I be a non-empty index set with a partial order <=, and A_i be a group for all i in I. Suppose that for every pair of indices i,j there is a map phi_ij:A_j ->A_i such that phi_jiphi_kj= phi_ki wheneveri<=j<=k, and phi_ii=1 for all i in I. Let P be the subset of elements(a_i) with i from I in the direct product D of A_i such

### Ring Theory: Direct and Inverse Limits, Homorphisms and Abelian Groups

Let I be a non-empty index set with a partial order<=. Assume that I is a directed set, that is, that for any pair i,j in I there is a,k in J such that i<=k and j<=k. Suppose that for every pair of indices i,j with i<=j ther is a map p_ij: A_i->A_j such that p_jkp_ij=p_ik whenever i<=j<=k and p_ii=1 for all i in I. Let B be the

### Surjective Ring Projections

Let m and n be positive integers with n dividing m. Prove that the natural surjective ring projection Z/mZ ->Z/nZ is also surjective on the units:(Z/mZ)^x ->(Z/nZ)^x

### Quotient Rings and Maximal Ideals

Let R be an integral domain, "m" a maximal ideal. Let S=R-m a) Prove that S^-1R is a local ring. b) Suppose R=Z, m=(5). Describe S^-1R.

### Quotient Rings, Laurent Series and Power Series

If F is a field, prove that the field of fractions of F[[x]] is the ring F((x)) of formal Laurent series. Show that the field of fractions of the power series ring Z[[x]] is properly contained in the field of Laurent series Q((x)). Ps. Here F[[x]] is the ring of formal power series in the indeterminate x with coefficients in

### Homomorphism of Commutative Rings, Prime Ideals, Maximal Ideals

Let phi:R->S be a homomorphism of commutative rings a) Prove that if P is a prime ideal of S then either phi^-1(P)=R or phi^-1(P) is a prime ideal of R. Apply this to the special case when R is a subring of S and phi is the inclusion homomorphism to deduce that if P is a prime ideal of S then PR is either R or prime ideal in

### Ring Theory: Euclidean Ring

Prove that a necessary and sufficient condition that the element 'a' in the Euclidean ring is a unit is that d(a) = d(1). Or, Prove that the element 'a' in the Euclidean ring is a unit if and only if d(a) = d(1).

### Ring theory proof fields

Modern Algebra Ring Theory (IX) The Field of Quotients of an Integral Domain Prove that the mapping &#966;:D&#8594;F defined by &#966;(a) =

### Ring theory proof in modern algebra

Modern Algebra Ring Theory (VIII) The Field of Quotients of an Integral Domain Prove the distributive law in F , the field of quotients of D, where D is the ring of integers.

### Ring Theory

Modern Algebra Ring Theory (VII) The Field of Quotients of an Integral Domain

### Ring Theory : Matrix Proof

Prove that if [a , b] = [a&#900;, b&#900;] and [c , d] = [c&#900;, d&#900;] then [a , b][c , d] = [a&#900;, b&#900;][c&#900;, d&#900;].

### Ring Theory : Division Rings

Let R be a ring such that the only right ideals of R are (0) and R. Prove that either R is a division ring or, that R is a ring with a prime number of elements in which ab = 0 for every a,b &#1028; R.

### Sets and Rings

Can any set that is not a group (Z for example) still be a ring or is it necessary that a set must be a group to be a ring? Please give an example and counter example.

Let R be a ring with the property that every element is either nilpotent or invertible. If a, b, c are in R with a and b nilpotent, show that ac, ca, and a + b are nilpotent. For the latter, first observe that a + b cannot equal 1. Conclude that Nil (R) is the set of all nilpotent elements of R. (nil radical Nil (R) is define

### Ring Theory/Largest two-sided ideal

Let I be a right ideal of a ring R and let A = {r in R: (R/I)r = 0}. Prove that A is the largest two-sided ideal of R contained in I.

### Units and Zero-divisor in a Commutative Ring with Identity

B8. Define what is meant by (a) a unit, (b) a zero-divisor in a commutative ring with identity. Show that an element in a communtative ring with identity (where 1 = 0) cannot be both a unit and a zero-divisor. Find an element in Z...Z which is neither a unit nor a zero-divisor. Show that... is a unit in .... Find a unit .

### Algebraic Structures: Groups, Rings, Fields and Matrices

A1. Which of the following binary operations on R... A2. Solve each of the following equations for x in a group G with a, b, c.... A3. Define what is meant by an abelian group. Let GL2(R) be the group of non-singular 2 ×2 real matrices under multiplication. Decide whether or not each of the following subgroups of GL2(R) is ab