CBSE Class 12 Mathematics 2024: question 3

Hints

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Step-by-step solution

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1. For a matrix of order $n$, $|\text{adj}A|=|A{|}^{n-1}$. Here $n=3$, so $|A{|}^2=8$.

   ½ mark

2. This gives $|A|=\pm 2\sqrt{2}$. Since $|A^T|=|A|$, the value among the options is $2\sqrt{2}$, option (D).

   ½ mark

Answer: $2\sqrt{2}$, option (D)

Revise the chapter

• Chapter: Determinants (notes, formulas, where marks are lost and every past question)