Characteristic polynomial: Difference between revisions

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In [[linear algebra]] the '''characteristic polynomial''' of a [[square matrix]] is a polynomial which has the [[eigenvalue]]s of the matrix as roots.
In [[linear algebra]] the '''characteristic polynomial''' of a [[square matrix]] is a polynomial which has the [[eigenvalue]]s of the matrix as roots.


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where ''X'' is an indeterminate and ''I''<sub>''n''</sub> is an [[identity matrix]].
where ''X'' is an indeterminate and ''I''<sub>''n''</sub> is an [[identity matrix]].
The characteristic polynomial is unchanged under [[similarity]], and hence be defined for an [[endomorphism]] of a [[vector space]], independent of choice of [[basis (linear algebra)|basis]].


==Properties==
==Properties==
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==Cayley-Hamilton theorem==
==Cayley-Hamilton theorem==
The '''Cayley-Hamilton theorem''' states that ''a matrix satisfies its own characteristic polynomial''.
The '''Cayley-Hamilton theorem''' states that ''a matrix satisfies its own characteristic polynomial''.[[Category:Suggestion Bot Tag]]

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In linear algebra the characteristic polynomial of a square matrix is a polynomial which has the eigenvalues of the matrix as roots.

Let A be an n×n matrix. The characteristic polynomial of A is the determinant

where X is an indeterminate and In is an identity matrix.

The characteristic polynomial is unchanged under similarity, and hence be defined for an endomorphism of a vector space, independent of choice of basis.

Properties

  • The characteristic polynomial is monic of degree n;
  • The set of roots of the characteristic polynomial is equal to the set of eigenvalues of A.

Cayley-Hamilton theorem

The Cayley-Hamilton theorem states that a matrix satisfies its own characteristic polynomial.