GATE ECE 2015 Set 3 | Question: 1

Question

For $A = \begin{bmatrix} 1 &\tan x \\ -\tan x &1 \end{bmatrix},$ the determinant of $A^{T}A^{-1}$ is

• A. $\sec^{2}x$
• B. $\cos 4x$
• C. $1$
• D. $0$