(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A = [tex]

\left| \begin{array}{ccc}

2 & 0 & 4 \\

0 & 4 & -8 \\

3 & -1 & 2 \end{array} \right|.\]

[/tex]

Find the LU decomposition.

3. The attempt at a solution

My question is why do you need to interchange rows 3 & 1 at the start of the problem? My initial attempt was to find the upper matrix using the format as given. I got

U = [tex]

\left| \begin{array}{ccc}

2 & 0 & 4 \\

0 & 4 & -8 \\

0 & 0 & -6 \end{array} \right|.\]

[/tex]

doesn't that satisfy the requirements for an U matrix?

According to the calculator I'm using the U matrix should be

[tex]

\left| \begin{array}{ccc}

3 & -1 & 2 \\

0 & 4 & -8 \\

0 & 0 & 4 \end{array} \right|.\]

[/tex]

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# Homework Help: LU Decomposition

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