Identity function: Difference between revisions

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In [[mathematics]], the '''identity function''' on a set ''X'' is the [[function (mathematics)|function]] from ''X'' to itself which maps each element to itself:
In [[mathematics]], the '''identity function''' on a set ''X'' is the [[function (mathematics)|function]] from ''X'' to itself which maps each element to itself:


:<math>\mbox{id}_X : x \mapsto x .\,</math>
:<math>\mbox{id}_X : x \mapsto x .\,</math>


The identity function is [[invertible function|invertible]] (and is its own [[inverse function]]).  It is a [[permutation]] of the set, and is the [[identity element]] of the [[symmetric group]] on ''X''.
The identity function is [[invertible function|invertible]] (and is its own [[inverse function]]).  It is a [[permutation]] of the set, and is the [[identity element]] of the [[symmetric group]] on ''X''.[[Category:Suggestion Bot Tag]]

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In mathematics, the identity function on a set X is the function from X to itself which maps each element to itself:

The identity function is invertible (and is its own inverse function). It is a permutation of the set, and is the identity element of the symmetric group on X.