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JEE Mains · Maths · STD 12 - 3 and 4 . metrices and determinant

Let \(A=\left[\begin{array}{cc}\frac{1}{\sqrt{10}} & \frac{3}{\sqrt{10}} \\ \frac{-3}{\sqrt{10}} & \frac{1}{\sqrt{10}}\end{array}\right]\) and \(B =\left[\begin{array}{rr}1 & - i \\ 0 & 1\end{array}\right]\), where \(i =\sqrt{-1}\). If \(M = A ^{ T } BA\), then the inverse of the matrix \(AM ^{2023} A ^{ T }\) is \(.........\)

  1. A \(\left[\begin{array}{cc}1 & -2023 i \\ 0 & 1\end{array}\right]\)
  2. B \(\left[\begin{array}{ll}1 & 0 \\ -2023 i & 1\end{array}\right]\)
  3. C \(\left[\begin{array}{ll}1 & 0 \\ 2023 i & 1\end{array}\right]\)
  4. D \(\left[\begin{array}{cc}1 & 2023 i \\ 0 & 1\end{array}\right]\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(\left[\begin{array}{cc}1 & 2023 i \\ 0 & 1\end{array}\right]\)

Step-by-step Solution

Detailed explanation

AA ^{ T }=\left[\begin{array}{cc}\frac{1}{\sqrt{10}} & \frac{3}{\sqrt{10}} \\ \frac{-3}{\sqrt{10}} & \frac{1}{\sqrt{10}}\end{array}\right]\left[\begin{array}{cc}\frac{1}{\sqrt{10}} & \frac{-3}{\sqrt{10}} \\ \frac{3}{\sqrt{10}} &…