1
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
2
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
$$ \left[\begin{array}{ccc} 1 & -1 & 1 \\ -8 & 7 & -5 \\ 5 & -4 & 3 \end{array}\right] $$
3
COMEDK 2024 Morning Shift
MCQ (Single Correct Answer)
+1
-0

$$ \text { If } x, y, z \text { are non zero real numbers, then inverse of matrix } A=\left[\begin{array}{lll} x & 0 & 0 \\ 0 & y & 0 \\ 0 & 0 & z \end{array}\right] \text { is } $$

A
$$ \frac{1}{x y z}\left[\begin{array}{lll} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{array}\right] $$
B
$$ \left[\begin{array}{ccc} 1 / x & 0 & 0 \\ 0 & 1 / y & 0 \\ 0 & 0 & 1 / z \end{array}\right] $$
C
$$ x y z\left[\begin{array}{ccc} 1 / x & 0 & 0 \\ 0 & 1 / y & 0 \\ 0 & 0 & 1 / z \end{array}\right] $$
D
$$ \frac{1}{x y z}\left[\begin{array}{lll} x & 0 & 0 \\ 0 & y & 0 \\ 0 & 0 & z \end{array}\right] $$
4
COMEDK 2024 Morning Shift
MCQ (Single Correct Answer)
+1
-0

$$ \text { If the matrix } A=\left(\begin{array}{cc} 1 & -1 \\ -1 & 1 \end{array}\right) \text { then } A^{n+1}= $$

A
$$ 2\left(\begin{array}{cc} 1 & -1 \\ -1 & 1 \end{array}\right) $$
B
$$ 2 n\left(\begin{array}{cc} 1 & -1 \\ -1 & 1 \end{array}\right) $$
C
$$ 2^{n+1}\left(\begin{array}{cc} 1 & -1 \\ -1 & 1 \end{array}\right) $$
D
$$ 2^n\left(\begin{array}{cc} 1 & -1 \\ -1 & 1 \end{array}\right) $$
COMEDK Subjects
EXAM MAP
Medical
NEETAIIMS
Graduate Aptitude Test in Engineering
GATE CSEGATE ECEGATE EEGATE MEGATE CEGATE PIGATE IN
Civil Services
UPSC Civil Service
Defence
NDA
Staff Selection Commission
SSC CGL Tier I
CBSE
Class 12