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Mathematics-Online course: Linear Algebra - Linear Systems of Equations - Approximation Problems

Approximative Solution of Over-determined Linear Systems of Equations


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If the right hand side $ b$ of a given LSE

$\displaystyle Ax=b
$

with $ m\times n$-coefficient matrix $ A$ is not contained in the linear hull of the columns of the coefficient matrix $ A$ (as is often the case for $ m>n$), that is, if

   Rang$\displaystyle (A) <$   Rang$\displaystyle \left([A,b]\right)\,
,
$

then the LSE has no solution. The LSE is a so called over-determined system. In this case it is possible to find an approximative solution by solving the approximation problem

$\displaystyle \Vert Ax-b \Vert _2 \to \min\,.
$

(Authors: App/Burkhardt/Höllig)

  automatically generated 4/21/2005