CraigsMaths

Mathematics Teaching for Learning

Posts Tagged ‘sarrus’

Finding determinants of a 3×3 matrix

Friday, August 8th, 2008

It is fairly simple to memorise the formula for the determinant of a 2×2 matrix:

\mathit{A}=\begin{bmatrix}<br />
a & b \\<br />
c & d<br />
\end{bmatrix}

\left|\mathit{A} \right|=ad-cb

Here we look at a simple approach that aids memorising the formula for a 3×3 matrix called Sarrus’ rule which will give you the determinant of a 3×3 matrix.

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