WBJEE · Maths · Matrices
If \(\mathrm{p}=\left[\begin{array}{lll}1 & \alpha & 3 \\ 1 & 3 & 3 \\ 2 & 4 & 4\end{array}\right]\) is the adjoint of the \(3 \times 3\) matrix \(\mathrm{A}\) and \(\operatorname{det} \mathrm{A}=4\), then \(\alpha\) is equal to
- A 4
- B 11
- C 5
- D 0
Answer & Solution
Correct Answer
(B) 11
Step-by-step Solution
Detailed explanation
\(|\mathrm{p}|=2 \alpha-6=(\operatorname{det} \mathrm{A})^2=16\) \(\Rightarrow \alpha=11\)
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