Matrices and Determinants · Mathematics · COMEDK
Start PracticeMCQ (Single Correct Answer)
COMEDK 2024 Evening Shift
$$
\text { If } 3 A+4 B^t=\left(\begin{array}{ccc}
7 & -10 & 17 \\
0 & 6 & 31
\end{array}\right) \text { and } 2 B-3 A^t=\left(\begin{array}{cc}
-1 & ...
COMEDK 2024 Evening Shift
$$
\text { If } A=\left[\begin{array}{cc}
5 a & -b \\
3 & 2
\end{array}\right] \text { and } A \operatorname{adj} A=A A^t \text {, then } 5 a+b \text ...
COMEDK 2024 Evening Shift
If the matrix $A$ is such that $$A\left(\begin{array}{cc}-1 & 2 \\ 3 & 1\end{array}\right)=\left(\begin{array}{cc}-4 & 1 \\ 7 & 7\end{array}\right)$$ ...
COMEDK 2024 Evening Shift
If $$A=\left[\begin{array}{ccc}0 & x & 16 \\ x & 5 & 7 \\ 0 & 9 & x\end{array}\right]$$ is a singular matrix then $$x$$ is equal to
COMEDK 2024 Morning Shift
$$
\text { If } P=\left[\begin{array}{lll}
1 & \alpha & 3 \\
1 & 3 & 3 \\
2 & 4 & 4
\end{array}\right] \text { is the adjoint of a } 3 \times 3 \text ...
COMEDK 2024 Morning Shift
If $$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}$$ is an id...
COMEDK 2024 Morning Shift
$$
\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
\en...
COMEDK 2024 Morning Shift
$$
\text { If the matrix } A=\left(\begin{array}{cc}
1 & -1 \\
-1 & 1
\end{array}\right) \text { then } A^{n+1}=
$$
COMEDK 2024 Morning Shift
If $$
\left[\begin{array}{lll}
1 & x & 1
\end{array}\right]\left[\begin{array}{ccc}
1 & 3 & 2 \\
2 & 5 & 1 \\
15 & 3 & 2
\end{array}\right]\left[\begi...
COMEDK 2023 Morning Shift
If $$A=\left[\begin{array}{ll}2 & 2 \\ 3 & 4\end{array}\right]$$, then $$A^{-1}$$ equals to
COMEDK 2023 Morning Shift
If $$A$$ is a matrix of order $$4 \operatorname{such}$$ that $$A(\operatorname{adj} A)=10 \mathrm{~I}$$, then $$|\operatorname{adj} A|$$ is equal to...
COMEDK 2023 Morning Shift
If $$A=\left[\begin{array}{cc}k+1 & 2 \\ 4 & k-1\end{array}\right]$$ is a singular matrix, then possible values of $$\mathrm{k}$$ are
COMEDK 2023 Evening Shift
$$
\text { If } A=\left(\begin{array}{ll}
1 & 2 \\
0 & 1
\end{array}\right) \quad P=\left(\begin{array}{cc}
\cos \theta & \sin \theta \\
-\sin \theta ...
COMEDK 2023 Evening Shift
$$A$$ and $$B$$ are invertible matrices of the same order such that $$\left|(A B)^{-1}\right|=8$$ if $$|A|=2$$ then $$|B|$$ is
COMEDK 2023 Evening Shift
If $$2 A+3 B=\left[\begin{array}{ccc}2 & -1 & 4 \\ 3 & 2 & 5\end{array}\right]$$ and $$A+2 B=\left[\begin{array}{lll}5 & 0 & 3 \\ 1 & 6 & 2\end{array}...
COMEDK 2023 Evening Shift
If $$\left[\begin{array}{ccc}2+x & 3 & 4 \\ 1 & -1 & 2 \\ x & 1 & -5\end{array}\right]$$ is a singular matrix, then $$x$$ is
COMEDK 2023 Evening Shift
Solution of $$x-y+z=4 ; x-2 y+2 z=9$$ and $$2 x+y+3 z=1$$ is
COMEDK 2022
If for any 2 $$\times$$ 2 square matrix A,
A (adj A) = $$\left[ {\matrix{
8 & 0 \cr
0 & 8 \cr
} } \right]$$, then find the value of det (A...
COMEDK 2022
If $$A = \left[ {\matrix{
a & 0 & 0 \cr
0 & a & 0 \cr
0 & 0 & a \cr
} } \right]$$, then $$|A||adj\,A|$$ is equal to
COMEDK 2022
If $$A = \left[ {\matrix{
{2 - k} & 2 \cr
1 & {3 - k} \cr
} } \right]$$ is a singular matrix, then the value of $$5k - {k^2}$$ is
COMEDK 2021
If for any 2 $$\times$$ 2 square matrix A, A (adj A) = $$\left[ {\matrix{
8 & 0 \cr
0 & 8 \cr
} } \right]$$, then the value of det (A)....
COMEDK 2021
If matrix $$A = \left[ {\matrix{
2 & { - 2} \cr
{ - 2} & 2 \cr
} } \right]$$ and $${A^2} = pA$$, then the value of $$p$$ is
COMEDK 2021
If $$A\,(adj\,A) = \left[ {\matrix{
{ - 2} & 0 & 0 \cr
0 & { - 2} & 0 \cr
0 & 0 & { - 2} \cr
} } \right]$$, then $$|adj\,A|$$ equals...
COMEDK 2020
If $$A = \left[ {\matrix{
1 & { - 1} & 1 \cr
2 & 1 & { - 3} \cr
1 & 1 & 1 \cr
} } \right],10B = \left[ {\matrix{
4 & 2 & 2 \cr
...
COMEDK 2020
If $$A = \left[ {\matrix{
0 & x & {16} \cr
x & 5 & 7 \cr
0 & 9 & x \cr
} } \right]$$ is singular, then the possible values of x are...
COMEDK 2020
If $$A = \left[ {\matrix{
1 & { - 2} & 2 \cr
0 & 2 & { - 3} \cr
3 & { - 2} & 4 \cr
} } \right]$$, then A . adj (A) is equal to
COMEDK 2020
The value of $$\left| {\matrix{
x & p & q \cr
p & x & q \cr
p & q & x \cr
} } \right|$$ is