Compute \(\det\left(\begin{pmatrix}1&2&3\\0&1&4\\5&6&0\end{pmatrix}\right)\) using expansion along the first row.
Question 9
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Compute \(\det\left(\begin{pmatrix}2&0&1\\3&0&4\\5&1&6\end{pmatrix}\right)\) by expanding along the second column.
Question 10
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A learner computes \(\det\left(\begin{pmatrix}1&2\\3&4\end{pmatrix}\right)\) as \(1\cdot4\) + \(2\cdot3\) = 10. Diagnose the error and give the correct determinant.