AoPSWiki
Looking for a challenging geometry text? Preparing for MATHCOUNTS or the AMC exams? Check out Art of Problem Solving's Introduction to Geometry by Richard Rusczyk.

Module

From AoPSWiki

Revision as of 00:25, 5 February 2009 by Jam (Talk | contribs)
(diff) ← Older revision | Current revision (diff) | Newer revision → (diff)

A module is a type of object which appears frequently in abstract algebra. It is a generalization of the concept of a vector space.

Specifically, given a ring R a (left) R-module is an abelian group (M,+) together with an operation R\times M\to M (called scalar multiplication) written as r\cdot x or rx, which satisfies the following properties:

For all a,b\in R, x,y\in M

(1) (a+b)x = ax+bx

(2) a(x+y) = ax+ay

(3) a(bx) = (ab)x

(4) 1x = x

We typically write M to mean the module as well as the underlying abelian group.

If R is a field then M is a vector space over R.

This article is a stub. Help us out by expanding it.

Try our innovative online adaptive learning system, Alcumus.
Over 1100 problems and 60+ video lessons. FREE!
© Copyright 2008 AoPS Incorporated. All Rights Reserved. • FoundationPrivacyContact Us