COMEDK · Maths · 21. Matrices
If \(A(\operatorname{adj} A)=\left[\begin{array}{lll}5 & 0 & 0 \\ 0 & 5 & 0 \\ 0 & 0 & 5\end{array}\right]\), then the value of \(|A|+|\operatorname{adj} A|\) is equal to
- A 25
- B 5
- C 125
- D 30
Answer & Solution
Correct Answer
(D) 30
Step-by-step Solution
Detailed explanation
Given \(A(\operatorname{adj} A) = 5I\), where \(I\) is the identity matrix of order \(3 \times 3\). Using the property \(A(\operatorname{adj} A) = |A|I\), we compare the given matrix with \(|A|I\).…
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