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Viewing Version 22 of 'linear independence'
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Title of object: linear independence
Canonical Name: LinearIndependence
Type: Definition

Created on: 2001-11-14 15:58:31
Modified on: 2003-02-03 00:40:40

Creator: rmilson
Modifier: rmilson
Author: rmilson
Author: NeuRet
Author: Daume

Classification: msc:15A03
Synonyms: linear independence=linearly independent

Revision comment (for changes between this and next version):

Changes for correction #7816 ('logical phrasing').

Preamble:

\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{graphicx}
\usepackage{xypic}
Content:

Let $V$ be a vector space over a
field $F$. Then for scalars $\lambda_1,~ \lambda_2,~ \ldots, ~\lambda_n \in F$ the vectors $\vec{v}_1,~ \vec{v}_2,~ \ldots,~ \vec{v}_n \in V$ are
linearly independent if the following condtion holds:
\[
\lambda_1\vec{v}_1+ \lambda_2 \vec{v}_2 + ~\cdots ~ +\lambda_n \vec{v}_n = 0 \mbox{ implies }
~ \lambda_1 = \lambda_2 = ~\ldots~ = \lambda_n=0
\]
Otherwise, if this conditions fails, the vectors are said to be linearly dependent. Furthermore, an infinite set of vectors is linearly independent if all \emph{finite} subsets are linearly
independent.

In the case of two vectors, linear independence means that one of these vectors is not a scalar multiple of the other.

As an alternate characterization of dependence, we have that a set of of vectors is linearly dependent if and only if some vector in the
set lies in the linear span of the other vectors in the set.