1
COMEDK 2025 Morning Shift
MCQ (Single Correct Answer)
+1
-0
If $A(t)=\left[\begin{array}{cc}\cos t & \sin t \\ -\sin t & \cos t\end{array}\right]$ then the product of $A(t)$ and $A(-t)$ is
A
Identity matrix
B
$A^2(t)$
C
Null matrix
D
$A^2(-t)$
2
COMEDK 2025 Morning Shift
MCQ (Single Correct Answer)
+1
-0
If $A=\left[\begin{array}{cc}1 & -2 \\ 4 & 5\end{array}\right] ; f(t)=t^2-3 t+7$ then $f(A)+\left[\begin{array}{cc}3 & 6 \\ -12 & -9\end{array}\right]=$
A
$\left[\begin{array}{ll}0 & 1 \\ 1 & 0\end{array}\right]$
B
$\left[\begin{array}{ll}1 & 1 \\ 0 & 0\end{array}\right]$
C
$\left[\begin{array}{ll}0 & 0 \\ 0 & 0\end{array}\right]$
D
$\left[\begin{array}{ll}1 & 0 \\ 0 & 1\end{array}\right]$
3
COMEDK 2025 Morning Shift
MCQ (Single Correct Answer)
+1
-0
For two matrices $A$ and $B$, given that $A^{-1}=\frac{1}{8} B$ then inverse of $(8 A)$ is
A
$\frac{1}{8} B$
B
8 B
C
$\frac{1}{64} B$
D
  B
4
COMEDK 2025 Morning Shift
MCQ (Single Correct Answer)
+1
-0
If $A=\left[\begin{array}{ccc}0 & 1 & -2 \\ -1 & 0 & 3 \\ 2 & -3 & 0\end{array}\right]$ then $A^{-1}$
A
equal to $-\frac{1}{12}(\operatorname{adj} A)$
B
equal to $-$12
C
equal to $\frac{1}{12}(\operatorname{adj} A)$
D
doesn't exit
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