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If a is a Square Matrix of Order 3 Such that |Adj A| = 64, Find |A|. - Mathematics

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Question

If A is a square matrix of order 3 such that |adj A| = 64, find |A|.

Solution

For any square matrix of order n, \[\left| adj A \right| = \left| A \right|^{n - 1} \]
\[ \Rightarrow 64 = \left| A \right|^2 \left[ \because \left| adj A \right| = 64 \right]\]
\[ \Rightarrow \left| A \right| = \pm 8\]

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Chapter 7: Adjoint and Inverse of a Matrix - Exercise 7.3 [Page 35]

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RD Sharma Mathematics [English] Class 12
Chapter 7 Adjoint and Inverse of a Matrix
Exercise 7.3 | Q 4 | Page 35

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