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Question
If |A| = 2, where A is 2 × 2 matrix, find |adj A|.
Solution
\[\text{ For any square matrix A of order n, }\left| adjA \right| = \left| A \right|^{n - 1} . \]
\[\text{ Given: }\hspace{0.167em} \left| A \right| = 2\]
Here, order is 2 .
\[ \Rightarrow \left| adjA \right| = \left| 2 \right|^{2 - 1} = 2\]
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