Abstract algebra Definition and 459 Threads

  1. Truecrimson

    The best edition of Fraleigh's Abstract Algebra?

    I'm going to buy A First Course in Abstract Algebra by Fraleigh. I've looked at 6th and 7th ed. 6th doesn't have a section on homology groups, but 7th does. From what I found from other threads here, 4th also has homology groups, and 3rd is at least good on group actions. (I haven't got to group...
  2. B

    Abstract Algebra, Division Ring question

    Homework Statement Let R = { [ a + b*sqrt(m) c + d*sqrt(m) ] } [ n(c - d*sqrt(m)) a - b*sqrt(m) ] (Sorry if the matrix is unclear... I can't get it space nicely. r11 = a + b*sqrt(m) r12 = c + d*sqrt(m) r21 = n(c -d*sqrt(m))...
  3. S

    Solve Abstract Algebra Homework: Finding Left Coset (1,2,3)H with Permutations

    One of my homework problems asks me to list the left coset (1,2,3)H where σ=(1,4,5)(2,3) and H=<σ>. I know that you have to take the do the permutation of (1,2,3)(1,4,5)(2,3) but i am not sure how you can do that? I got (1,2,3)H={(1,2,3)(3)(1,2,4,5)} but i do not think that is right
  4. J

    Abstract Algebra, rings, zero divisors, and cartesian product

    The problem states: Let R and S be nonzero rings. Show that R x S contains zero divisors. I had to look up what a nonzero ring was. This means the ring contains at least one nonzero element. R x S is the Cartesian Product so if we have two rings R and S If r1 r2 belong to R and s1 s1...
  5. E

    Abstract Algebra: conjugates of cyclical groups

    Homework Statement If G is a group with operation * and \alpha,\beta\in G, then \beta\ast\alpha\ast\beta^{-1} is called a conjugate of G. Compute the number of conjugates of each 3-cycle in S_{n} (n\geq3). Homework Equations The Attempt at a Solution For any group S_{n} there...
  6. N

    How Does Cycle Length Relate to Element Order in Group Representations?

    abstract algebra question?? here is the problem from abstract algebra, anyone could help? Thanks a lot! let G be a finite group. Show that in the disjoint cycle form of the right regular representation Tg(x)=xg of G each cycle has length | g |. (Tg(x) means T sub g of x) loofinf...
  7. A

    Abstract algebra vector space problem

    Homework Statement We have a vector space (V, R, +, *) (R being Real numbers, sorry I couldn't get latex work..) with basis V = span( v1,v2). We also have bijection f: R² -> V, such as f(x,y) = x*v1+y*v2. Assume you have inner-product ( . , . ): V x V -> R. ( you can use it abstractly and...
  8. C

    Abstract algebra proof involving prime numbers

    The question states prove, If p is prime and p | a^n then p^n | a^n I am pretty sure I have i just may need someone to help clean it up. There are two relevant theorems i have for this. the first says p is prime if and if p has the property that if p | ab then p | a or p | b the...
  9. G

    Abstract Algebra- A simple problem with Cosets

    I need to find all the cosets of the subgroup H={ [0], [4], [8] ,[12] } in the group Z_16 and find the index of [Z16 : H]. Help would be appreciated :)
  10. O

    Abstract Algebra: Homomorphism f Determined by f(1) in Z

    Homework Statement Let R be any ring and f:Z→R a homomorphism. a)Show that f is completely determined by the single value f(1) b)Determine all possible homomorphisms f in the case when R = Z. Homework Equations The Attempt at a Solution This question has me totally confused...
  11. E

    Abstract Algebra- homomorphisms and Isomorphisms, proving not cyclic

    1. Suppose that H and K are distinct subgroups of G of index 2. Prove that H intersect K is a normal subgroup of G of index 4 and that G/(H intersect K) is not cyclic. 2. Homework Equations - the back of my book says to use the Second Isomorphism Theorem for the first part which is... If K...
  12. S

    Proof: a^3 divides b^2 implies a divides b in Abstract Algebra.

    Let a, b be integers a,b>0 show that if a^3 | b^2 then a|b (Consider the prime factorization of a and b) I've tried setting up generic prime factorization of a and b but then don't get any where, I'm not very strong at this subject. Any kind of hints / where to start would help a lot...
  13. C

    How many groups are there of order 7?

    How many groups are there of order 7. I just need to know this to continue with an assignment. Thanks.
  14. O

    Abstract Algebra: Polynomials problem

    Homework Statement Let f(x)=x5-x2-1 \in C and x1,...,x5 are the roots of f over C. Find the value of the symmetric function: (2x1-x14).(2x2-x24)...(2x5-x54) Homework Equations I think, that I have to use the Viete's formulas and Newton's Binomial Theorem. The Attempt at a...
  15. P

    Any good book to review abstract algebra?

    Hi, I am a junior and a math major, and I am almost done with my year-long abstract algebra sequence for undergraduates. While I found the materials interesting, I feel like I got lost at some places in this course, and I would like to review (or in some topics, relearn) the materials that I...
  16. T

    Proving the Center of a Group Generated by x and y is {e, x^n}

    Homework Statement Let G=<x, y| x^{2n}=e, x^n=y^2, xy=yx^{-1}>. Show Z(G)={e, x^n}. Homework Equations The Attempt at a Solution So I tried breaking this up into cases: Case 1: If n=1. then |x|=1 or 2. If |x|=1, then x=e and x would obviously be in the center. If |x|=2, then xy=yx (since...
  17. T

    Abstract Algebra: Find Generators & Relations for Z2+Z2+Z2

    Homework Statement What is the minimum number of generators needed for Z2+Z2+Z2? Find a set of generators and relations for this group. Homework Equations The Attempt at a Solution I think it is obvious that the minimum amount of generators that you need is three, with Z2+Z2+Z2 =...
  18. M

    Understanding in abstract algebra

    In algebra, do you just base your understanding off the pure definitions and groups? I am learning some multilinear algebra, seeing a lot of talk about rings, algebras, modules, etc. and I can't help but thinking it's all just frivolous, pointless definitions. That's partly because I just can...
  19. K

    Find d when d|n2+n-2, d|n3+2n-1 & d=1 (mod 2), d > 1

    Let d=GCD(n2+n-2,n3+2n-1). Find d if d=1(mod 2) & d > 1. So we know d|n2+n-2 & d|n3+2n-1. My question is simply this, the professor wrote down hence d|n3+n2-2n, right after what is written above. But I'm just not seeing how you get that combination. I understand how to work the...
  20. T

    Abstract Algebra Homomorphism Proof

    Homework Statement Let G and H be two groups. If f: G \rightarrow H is a homomorphism, a \in G and b = f(a). If ord(a) = n, ord(b) = m, then n is a multiple of m. (Let e_{1} be the identity of G and e_{2} be the identity of H) I have to prove that n is a multiple of m. Homework Equations...
  21. T

    Abstract Algebra: Finding Conjugates

    Homework Statement Consider this group of six matrices: Let G = {I, A, B, C, D, K}, Matrix Multiplication> I =\begin{bmatrix}1 & 0\\0 & 1\end{bmatrix} A =\begin{bmatrix}0 & 1\\1 & 0\end{bmatrix} B =\begin{bmatrix}0 & 1\\-1 & -1\end{bmatrix} C =\begin{bmatrix}-1 & -1\\0 & 1\end{bmatrix} D...
  22. H

    Should I take complex analysis or abstract algebra?

    Being a high school student who will be going into physics, should I take complex analysis or abstract algebra in the fall? I can't take both at once, and I am set to take intro to QM (I will already have taken Calc I-III, an introductory functional analysis course, and linear algebra. I also...
  23. C

    Is R={0, 2, 4, 6, 8} a Field under Addition and Multiplication Modulo 10?

    Homework Statement Let R={0, 2, 4, 6, 8} under addition and multiplication modulo 10. Prove that R is a field. Homework Equations A field is a commutative ring with unity in which every nonzero element is a unit. The Attempt at a Solution I know that the unity of R is 6, and that...
  24. K

    Binary Operation, Abstract Algebra

    Define a binary operation on Z, the set of integers by the equation m * n = m + n + mn. Which of the following statemnts is / are true about the binary structure of Z with * 1) * is not associative 2) There is no element e belonging to Z such that for every z belonging to Z, z*e = e*z = z 3)...
  25. E

    Abstract Algebra: Show that 2Z + 5Z = Z

    Homework Statement Show that 2\mathbb{Z} + 5\mathbb{Z} = \mathbb{Z}Homework Equations where 2Z + 5Z = {a+b | a in 2Z and b in 5Z} = ZThe Attempt at a Solution For any n in Z, we can write n= (5-4)n = 5n +(-4)n = 5n + 2(-2n) And since 5n is in 5Z and 2(-2n) is in 2Z, we can form Z from any...
  26. T

    Abstract Algebra: Proving/Disproving |a|=|b| if |a^2|=|b^2|

    Homework Statement If |a^2|=|b^2|, prove or disprove that |a|=|b|. Homework Equations The hint I was given is that let a be an element of order 4n+2 and let the order of b=a2 The Attempt at a Solution I can disprove this by looking at examples, such as in the group Z20 with...
  27. T

    Abstract algebra cyclic subgroups

    Homework Statement Suppose that G is a group with exactly eight elements of order 10. How many cyclic subgroups of order 10 does G have? Homework Equations The Attempt at a Solution I really don't have a clue how to solve this, any help would be greatly appreciated.
  28. icystrike

    Abstract Algebra: Schwarz Inequality Homework

    Homework Statement This is part of the proof of Schwarz inequity. Please help me understand the following equation , i think it should not be a equal sign instead it should be greater or equal to. Homework Equations The Attempt at a Solution
  29. I

    Abstract Algebra: a problem about ideal

    Homework Statement Let J be the set of all polynomials with zero constant term in Z[x]. (Z=integers) a.) Show that J is the principal ideal (x) in Z[x]. b.) Show that Z[x]/J consists of an infinite number of distinct cosets, one for each n\inZ. Homework Equations The Attempt at...
  30. T

    Is C(a) isomorphic to C(gag-1) for elements a and g in a group?

    Homework Statement If a and g are elements of a group, prove that C(a) is isomorphic to C(gag-1) Homework Equations I have defined to mapping to be f:C(gag-1) to C(a) with f(h)=g-1hg. I have no idea if this is right. The Attempt at a Solution I don't have a clue at the solution...
  31. M

    Abstract Algebra: Solving Stumping Questions | αη = β and G is Abelian

    I have 2 algebra questions which are stumping me, I just can't seem to use my notes to figure them out! 1. Let α, β ∈ S[SIZE="1"]17 where α = (17 2)(1 2 15 17 ), β = (2 3 16)(6 16 17 ). Determine η, as a product of disjoint cycles, where αη = β. 2. Let G be a group in which a^2 = 1 for all...
  32. T

    Abstract Algebra: Proving whether H is a subgroup.

    Homework Statement Let R = {all real numbers}. Then <R,+> is a group. (+ is regular addition) Let H = {a|a \epsilon R and a2 is rational}. Is H closed with respect to the operation? Is H closed with respect to the inverse? Is H a subgroup of G? Homework Equations N/A The Attempt at a...
  33. C

    Abstract algebra. proving things about U(n)

    Homework Statement prove that if g is in Z*_n then g^2=1, so g has order 2 or is the identity. show that the largest value of n for which every non identity element of Z*_n has order 2. which are these others. Homework Equations Z*_n = U(n) different notation it is the the group of co...
  34. J

    Help with abstract algebra proof

    prove that a finite ring with identity has characteristic n for some n>0. been trying for a while getting nowhere any ideas?
  35. L

    Abstract algebra: Rings and Ideals

    Homework Statement The problem is to show that a subset A of a ring S is an ideal where A has certain properties. S is a ring described as a cartisian product of two other rings (i.e., S=(RxZ,+,*)). I have already proved that A is a subring of S and proved one direction of the definition of an...
  36. O

    Abstract Algebra: Is S(3) Isomorphic to Z(6)?

    Homework Statement Is the symmetric group s(3) isomorphic to Z(6), the group of integers modulo six with addition (mod 6) as its binary operationHomework Equations Basically i know that the symmetric group is all the different permutations of this set and that there are six of them. I also...
  37. D

    Why Are Rings in Abstract Algebra Important?

    Ok so I am not a math major and i haven't taken an abstract algebra class but i am curoius about the subject. I have been watching video lectures at UCCS at http://cmes.uccs.edu/Fall2007/Math414/archive.php?type=valid and the proffessor talks about groups and rings. In the introduction the...
  38. W

    Abstract Algebra Concept-based Question

    I have no abstract algebra background (only matrices and calculus and stats) but this problem came up in one of my classes and this time I'm completely clueless: Homework Statement A group is cyclic if an element, g, of the group generates the entire group in the sense that if h is any...
  39. U

    Discussion group for abstract algebra? I'd be interested

    Hi everyone, I've just finished year 11 here in Australia and I've been reading some notes on abstract algebra just out of curiosity. I have had a little difficulty grasping the concepts, and I've read up on some linear algebra (up to the point of Euclidean n-space - haven't yet read about...
  40. P

    Abstract Algebra: Commutative Subgroup

    Homework Statement Let G be a group and let a, b be two fixed elements which commute with each other (ab = ba). Let H = {x in G | axb = bxa}. Prove that H is a subgroup of G. Homework Equations None The Attempt at a Solution I'm using the subgroup test. I know how to show...
  41. P

    I want to get A's in analysis and abstract algebra

    I just finished my first quarter of analysis (Text: Rudin's PMA) and abstract algebra (Text: Beachy and Blair) courses. I must say I really enjoyed these courses, and I feel like I learned a lot from them. However, I still ended up getting B+'s from both of these courses. While I'm not...
  42. K

    Is a Finite Group Without a Subgroup Isomorphic to Z_p X Z_p Always Cyclic?

    1. If G is a finite group that does not contain a subgroup isomorphic to Z_p X Z_p for any prime p. prove that G is cyclic im stumped. i don't understand the 'does not contain a subgroup isomorphoc to Z_p X Z_p part. ive tried using cauchy's theorem for abelian group: if G is a finite...
  43. V

    Abstract algebra: systems of differential linear equations

    Homework Statement Solve the inhomogeneous differential equation dX/dt=AX+B in terms of the solutions to the homogeneous equation dX/dt=AX. Homework Equations A is an nxn real or complex matrix and X(t) is an n-dimensional vector-valued function. If v is an eigenvector for A with...
  44. D

    Abstract Algebra: Proving E=F(a^p)

    Homework Statement Let F be a field of characteristic p>0 and let E = F(a) where a is separable over F. Prove that E=F(a^p). Homework Equations The Attempt at a Solution I know that maybe show how mod F(a) = mod F(a^p) or something around there.
  45. V

    Proving Coset Properties in Abstract Algebra

    Question: Prove the following properties of cosets. Given: Let H be a subgroup and let a and b be elements of G. H\leq\ G Statement: aH=bH \ if\ and\ only\ if\ a^{-1}b\ \epsilon\ H The statement is what I have to prove. My issue is I don't know how to start off the problem. When I...
  46. V

    Abstract Algebra - Orbit of a permutation

    For this problem, I have to find all orbits of given permutation. \sigma: \mathbb{Z} \rightarrow \mathbb{Z} Where, \sigma(n)=n-3 Now, the problem is I do not know how to approach this permutation in the given format. All the permutations I dealt with were in the form: \mu...
  47. D

    Abstract Algebra Problem (should be easy)?

    Homework Statement List all the elements of GL_N(\mathbb{Z}/2\mathbb{Z}). Find the order of each element, and show it is not abelian. The Attempt at a Solution I am confused right from the get go about GL_n(\mathbb{Z}/2\mathbb{Z}). I think the L_n(\mathbb{Z}/2\mathbb{Z}) part...
  48. D

    Abstract Algebra: Homomorphism

    Hey all, I`ve been working at this "proof" for several hours now, have put it away several times thinking that maybe I`ll get it if I leave it alone for a bit...has not worked =] It has 2 parts, I think I have proven the first part, but the second one really just stumps me =| 1. Show that a...
  49. B

    Abstract algebra question chapter 1.2

    Homework Statement prove that if 2 does not divide a then 24 divides a^2-1 Homework Equations I know that if 2 does not divide a then a is odd. I proved that the square for all odd integers are of the form 8K+1 I also proved the square of any integer is either in the form...
  50. J

    Is Artin's Algebra Book Suitable for Beginners?

    How hard is Artin's Algebra book to understand? For a student who has not had any upper level (proof based) math classes beyond calculus, is it doable if you are sufficiently motivated?
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