JEE Mains · Maths · STD 12 - 3 and 4 . metrices and determinant
The number of matrices \(A=\left[\begin{array}{ll}a & b \\ c & d\end{array}\right]\), where a \(, b, c, d \in\{-1,0,1,2,3, \ldots \ldots, 10\}\), such that \(A=A^{-1}\), is
- A \(51\)
- B \(52\)
- C \(53\)
- D \(50\)
Answer & Solution
Correct Answer
(D) \(50\)
Step-by-step Solution
Detailed explanation
\(A =\left[\begin{array}{ll} a & b \\ c & d \end{array}\right]\) Given \(A = A ^{-1}\) \(\therefore A ^{2}= A \cdot A ^{-1}= I\)…
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