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Question
Choose the correct alternative.
If A is a 2 x 2 matrix such that A(adj. A) = `[(5, 0),(0, 5)]`, then |A| = _______
Options
0
5
10
25
Solution
5
Explanation:
A(adj A) = |A| I
A(adj A) = `[(5, 0),(0, 5)] = 5[(1, 0),(0, 1)]`
∴ |A| = 5.
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