1
COMEDK 2024 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

$$ \text { A square matrix } P \text { satisfies } P^2=I-P \text { where } I \text { is identity matrix. If } P^n=5 I-8 P \text {, then } n \text { is equal to } $$

A
4
B
6
C
7
D
5
2
COMEDK 2024 Afternoon Shift
MCQ (Single Correct Answer)
+1
-0

If $$A=\left[\begin{array}{lll}5 & 0 & 4 \\ 2 & 3 & 2 \\ 1 & 2 & 1\end{array}\right] \quad B^{-1}=\left[\begin{array}{lll}1 & 3 & 3 \\ 1 & 4 & 3 \\ 1 & 3 & 4\end{array}\right]$$ then $$(A B)^{-1}$$ is equal to

A
$$ \left[\begin{array}{ccc} -2 & 19 & -27 \\ -2 & 18 & -25 \\ 3 & 29 & 42 \end{array}\right] $$
B
$$ \left[\begin{array}{lll} -2 & 19 & -27 \\ -2 & 18 & -25 \\ -3 & 29 & -42 \end{array}\right] $$
C
$$ \left[\begin{array}{ccc} -2 & -2 & -3 \\ 19 & 18 & 29 \\ -27 & -25 & -42 \end{array}\right] $$
D
$$ \left[\begin{array}{lll} 2 & -19 & 27 \\ 2 & -18 & 25 \\ 3 & -29 & 42 \end{array}\right] $$
3
COMEDK 2024 Morning Shift
MCQ (Single Correct Answer)
+1
-0

$$ \text { If } P=\left[\begin{array}{lll} 1 & \alpha & 3 \\ 1 & 3 & 3 \\ 2 & 4 & 4 \end{array}\right] \text { is the adjoint of a } 3 \times 3 \text { matrix } A \text { and }|A|=4 \text { then } \alpha \text { is equal to } $$

A
11
B
4
C
0
D
5
4
COMEDK 2024 Morning Shift
MCQ (Single Correct Answer)
+1
-0

If $$A=\left[\begin{array}{ccc}-1 & 1 & 2 \\ 1 & 2 & 3 \\ 3 & 1 & 1\end{array}\right]$$ then the inverse of $$(A I)^t$$ (where $$\mathrm{I}$$ is an identity matrix) is

A
$$ \left[\begin{array}{ccc} 1 & -8 & 5 \\ -1 & 7 & -4 \\ 1 & -5 & 3 \end{array}\right] $$
B
$$ \left[\begin{array}{ccc} -1 & 1 & -1 \\ 8 & -7 & 5 \\ -5 & 4 & -3 \end{array}\right] $$
C
$$ \left[\begin{array}{ccc} 1 & 8 & -5 \\ -1 & 7 & -4 \\ 0 & 5 & 3 \end{array}\right] $$
D
$$ \left[\begin{array}{ccc} 1 & -1 & 1 \\ -8 & 7 & -5 \\ 5 & -4 & 3 \end{array}\right] $$
COMEDK Subjects
EXAM MAP