Difference between revisions of "Vector space"
| Line 25: | Line 25: | ||
Let <math>X</math> be a subset of some vector space <math>V</math>. Then it can be proved that the set of all linear combinations of the elements of <math>X</math> forms a vector space. This space is said to have been generated by <math>X</math>, and is called the linear manifold <math>M(X)</math> of <math>X</math>. | Let <math>X</math> be a subset of some vector space <math>V</math>. Then it can be proved that the set of all linear combinations of the elements of <math>X</math> forms a vector space. This space is said to have been generated by <math>X</math>, and is called the linear manifold <math>M(X)</math> of <math>X</math>. | ||
| + | |||
| + | == Generating Subset == | ||
| + | |||
| + | If <math>X</math> is a subset of a vector space <math>V</math>, such that <math>M(X) = V</math>, <math>X</math> is said to be a generating subset of <math>V</math>. | ||
Revision as of 13:59, 4 November 2006
This article is a stub. Help us out by expanding it.
A vector space over a field (frequently the real numbers) is an object which arises in linear algebra and abstract algebra. A vector space
over a field
consists of a set (of vectors) and two operations, vector addition and scalar multiplication, which obey the following rules:
Contents
Axioms of a vector space
- Under vector addition, the set of vectors forms an abelian group. Thus, addition is associative and commutative and there is an additive identity (usually denoted
) and additive inverses.
- Scalar multiplication is associative, so if
and
then
.
- Scalar multiplication is distributive over both vector and scalar addition, so if
and
then
.
- if
, 
Subspaces
If
, and
is a vector space itself, then it is called a subspace of
.
Independent Subsets
Let
be a vector space over the complex field. Let
be a subset of
such that no linear combination of elements of
with coefficients not all zero gives the null vector. Then
is said to be a linearly independent subset of
.
Linear Manifolds
Let
be a subset of some vector space
. Then it can be proved that the set of all linear combinations of the elements of
forms a vector space. This space is said to have been generated by
, and is called the linear manifold
of
.
Generating Subset
If
is a subset of a vector space
, such that
,
is said to be a generating subset of
.