If A is a \(3\times3\) matrix such that \(|5\cdot \operatorname{adj}A|=5\), then \(|A|\) is equal to :
Show Hint
- \(\pm\dfrac{1}{5}\)
- \(\pm5\)
- \(\pm1\)
- \(\pm\dfrac{1}{25}\)
The Correct Option is A
Solution and Explanation
So \(125|A|^2=5\Rightarrow |A|^2=\frac{1}{25}\Rightarrow |A|=\pm\frac15\).
Answer: (1) \(\pm\frac{1}{5}\)
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