What is Algebra: Definition and 999 Discussions

Algebra (from Arabic: الجبر‎, romanized: al-jabr, lit. 'reunion of broken parts, bonesetting') is one of the broad areas of mathematics, together with number theory, geometry and analysis. In its most general form, algebra is the study of mathematical symbols and the rules for manipulating these symbols; it is a unifying thread of almost all of mathematics. It includes everything from elementary equation solving to the study of abstractions such as groups, rings, and fields. The more basic parts of algebra are called elementary algebra; the more abstract parts are called abstract algebra or modern algebra. Elementary algebra is generally considered to be essential for any study of mathematics, science, or engineering, as well as such applications as medicine and economics. Abstract algebra is a major area in advanced mathematics, studied primarily by professional mathematicians.
Elementary algebra differs from arithmetic in the use of abstractions, such as using letters to stand for numbers that are either unknown or allowed to take on many values. For example, in



x
+
2
=
5


{\displaystyle x+2=5}
the letter



x


{\displaystyle x}
is an unknown, but applying additive inverses can reveal its value:



x
=
3


{\displaystyle x=3}
. Algebra gives methods for writing formulas and solving equations that are much clearer and easier than the older method of writing everything out in words.
The word algebra is also used in certain specialized ways. A special kind of mathematical object in abstract algebra is called an "algebra", and the word is used, for example, in the phrases linear algebra and algebraic topology.
A mathematician who does research in algebra is called an algebraist.

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  1. F

    Constantly accelerating rocket algebra problem

    Homework Statement Rocket is accelerating constantly. Let S' be instantaneous rest frame of rocket and S be frame in which rocket is observed moving at velocity v. Homework Equations Given: $$ dv = dv' (1 - v^2) $$ Must prove: $$ \frac{dv}{dt} = \frac{dv'}{dt'} (1 -...
  2. M

    Dirac Trace Algebra: Which Gamma Matrices Matter?

    Homework Statement This isn't a homework problem; it's just something I'm working on and I'm a little confused as to how to go about dealing with what I have. I have several traces of Dirac's gamma matrices, and I know that the trace of an odd number of gamma matrices is zero. So my first...
  3. C

    Linear algebra, can A be one-to-one given a case

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  4. Z

    MHB Linear Algebra: Analyzing A Linear Transformation

    Hey, I need help with part D2. My explanation is not right so I honestly do not know what I am suppose to write. My assignment is attached to this thread.
  5. RJLiberator

    Abstract Algebra: Bijection, Isomorphism, Symmetric Sets

    Homework Statement Suppose X is a set with n elements. Prove that Bij(X) ≅ S_n. Homework Equations S_n = Symmetric set ≅ = isomorphism Definition: Let G and G2 be groups. G and G2 are called Isomorphic if there exists a bijection ϑ:G->G2 such that for all x,y∈G, ϑ(xy) = ϑ(x)ϑ(y) where the...
  6. Y

    Intro Math Good math books for pre algebra

    Hi, I'm looking for a good math book for a 10 year old. He's actually very gifted, as he's able to pick up things like factors and equalities pretty fast. The thing is I'm not a math teacher and I think he needs to go over basic geometry and arithmetic before moving on to algebra, basically...
  7. Y

    Linear Algebra - Hooke's Law Problem

    Homework Statement For the system of springs a) Assemble the stiffness matrix K and the force-displacement relations, K*u = f b) Find the L*D*L^T factorization of K. Use Matlab to solve c) Use the boundary conditions and applied forces to find the displacements Homework EquationsThe Attempt...
  8. Y

    Linear Algebra - Left Null Space

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  9. Asleky

    Dynamics: Incline Slope Derivation Simplification

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  10. T

    I Linear Transformation notation

    I'm confused about the notation T:R^n \implies R^m specifically about m. From my understanding if n=2 then (x1, x2). Are we transforming n=2 to another value m for example (x1, x2, x3)?
  11. F

    I Difference between 'Field' (algebra) and 'Field' (geometry)

    I am trying to build up a kind of mind map of the following: Module (eg. vector space) Ring (eg Field) Linear algebra (concerning vectors and vector spaces, from what I understood) Multilinear Algebra (analogously concerning tensors and multi-linear maps) Linear maps & Multilinear maps The...
  12. kevin2016

    A What is the closed-form solution using ALS algorithm to optimize

    C \in \mathbb{R}^{m \times n}, X \in \mathbb{R}^{m \times n}, W \in \mathbb{R}^{m \times k}, H \in \mathbb{R}^{n \times k}, S \in \mathbb{R}^{m \times m}, P \in \mathbb{R}^{n \times n} ##{S}## and ##{P}## are similarity matrices (symmetric). ##\lambda##, ##\alpha## and ##\beta## are...
  13. G

    MHB Completing the square using algebra tiles

    I'm trying to create a square using algebra tiles. The question is x^2 + 4x + 5. I know how to do it without the algebra tiles but I don't know how to do it with the algebra tiles. Can anyone give me a hand with this?
  14. R

    Finding Coordinate Matrix for Linear Transformation T

    Homework Statement Hey, I posted another question yesterday, and thanks to the kindness and brilliance of hall of ivy, I was able to solve it. However when I apply the same logic to this new question I cannot seem to get it, can someone explain or show me how to do this question. Consider the...
  15. R

    Linear Algebra matrix linear transformation

    Homework Statement Consider the linear transformation T from V = P2 to W = P2 given by T(a0 + a1t + a2t2) = (−4a0 + 2a1 + 3a2) + (2a0 + 3a1 + 3a2)t + (−2a0 + 4a1 + 3a2)t^2 Let E = (e1, e2, e3) be the ordered basis in P2 given by e1(t) = 1, e2(t) = t, e3(t) = t^2 Find the coordinate matrix...
  16. O

    Algebra Sheldon Axler's Algebra and Trig/Precalculus for proofs?

    Can someone tell me if Axler's texts use proofs? I'm looking for a book that teaches proofs at the high school level. Something other than a geometry text.
  17. G

    Linear algebra: Prove the statement

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  18. A

    Solve Notation Puzzle: Vertical Bars in Equations Homework

    Homework Statement I have these two equations from this paper: https://www.scribd.com/doc/299960566/Spiral Homework Equations What are the vertical bars next to the drawn red starts supposed to indicate in this context? I'm trying to implement these equations into a program but I'm totally...
  19. RJLiberator

    [Abstract Algebra] GCD and Relatively Prime Proof

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  20. RJLiberator

    [Abstract Algebra] Field and Polynomial Root problem

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  21. J

    Linear Algebra: Determine Span of {(1, 0, 3), (2, 0, -1), (4, 0, 5), (2, 0, 6)}

    Homework Statement Determine whether the set spans ℜ3. If the set does not span ℜ3 give a geometric description of the subspace it does span. s = {(1, 0, 3), (2, 0, -1), (4, 0, 5), (2, 0, 6)} Homework EquationsThe Attempt at a Solution I am having trouble with the second part of this problem...
  22. RJLiberator

    Factoring Polynomials [Abstract Algebra]

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  23. W

    Name for "Concatenation Operator"(Rel. Algebra, SQL)

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  24. Duncan R

    Linear Algebra A search for a classic, out of print Linear Algebra textbook

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  25. Q

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  26. S

    Susy algebra trivial question

    Dear All Am trying to study supersymmetry algebra. We start by constructing the graded poincare algebra by considering the direct sum of the ordinary Poincare algebra L0 with a subspace L1 spanned by the spinor generators Qa where a runs from 1 to 4 ( L1 is not a lie algebra ). So now we have...
  27. M

    Where Can I Find Accredited Online Physics with Algebra Courses?

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  28. anemone

    MHB Prove $\dfrac{a^3}{c}+\dfrac{b^3}{d}\ge 1$ with Algebra Challenge

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  29. P

    Linear algebra : Doing a proof with a square matrix

    Homework Statement Show that all square matrix (A whatever) can be written as the sum of a symmetric matrix and a anti symmetric matrix. Homework Equations I think this relation might be relevant : $$ A=\frac{1}{2}*(A+A^{T})+\frac{1}{2}*(A-A^{T}) $$ The Attempt at a Solution I know that we...
  30. RJLiberator

    Abstract algebra Polynomials and Prime

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  31. RJLiberator

    Finding coefficients for reducibility (Abstract Algebra)

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  32. RJLiberator

    Simple Abstract Algebra Proof: T(0_r) = 0_s

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  33. G

    Linear algebra: Find the matrix of linear transformation

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  34. H

    Am I Hallucinating? (confusion in geometric algebra)

    I'm learning geometric algebra. There is a very simple statement which I think is wrong. But it must be right, because all the experts say so. Arrg! The only properties used are 1a = a1 = a aa = 1 if b<>a then ab = -baTheir claim is that abcdabcd = -1. Let's see: aa = 1 abab = -abba =...
  35. G

    Linear algebra: Prove that the set is a subspace

    Homework Statement Let U is the set of all commuting matrices with matrix A= \begin{bmatrix} 2 & 0 & 1 \\ 0 & 1 & 1 \\ 3 & 0 & 4 \\ \end{bmatrix}. Prove that U is the subspace of \mathbb{M_{3\times 3}} (space of matrices 3\times 3). Check if it contains span\{I,A,A^2,...\}. Find the...
  36. Mastermind01

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  37. I

    Schools Any good YouTube channels for 'College Physics' (algebra)

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  38. RJLiberator

    Abstract Algebra: Another Ring Proof

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  39. RJLiberator

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  40. ahmed habala

    Hi all -- I need a good reference about linear algebra

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  41. TheMathNoob

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  42. P

    Solutions to Hungerford's "Abstract Algebra" 3rd Ed.

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  43. G

    Linear algebra: Find the span of a set

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  44. G

    Linear algebra: Finding a basis for a space of polynomials

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  45. kroni

    Find Lorentzian Scalar Product on 4-D Lie Algebra G

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  46. T

    Algebra What is the best book to learn algebra 1 from?

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  47. anemone

    MHB Proving System of Equations for Algebra Challenge

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  48. J

    Linear Algebra Which one of these Linear Algebra textbooks is the best?

    I want a good linear algebra textbook in order to learn to use linear algebra in physics but also to use it in more theoretical mathematics courses. I hope that with this poll i will also help others that want to study from a proper Linear Algebra textbook.
  49. T

    How can i solve joint proportion?

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