Question
Suppose $X =\left[x_{i j}\right]$ a matrix, where
$
X=\left[\begin{array}{ccc}
1 & -1 & 2 \\
3 & 4 & -5 \\
2 & -1 & 3
\end{array}\right]
$
Then matrix $Y =\left[m_{i j}\right]$, where $m_{i j}=$ minor of $x_{i j}$ :

Answer

(D)
Here $X=\left[\begin{array}{ccc}1 & -1 & 2 \\ 3 & 4 & -5 \\ 2 & -1 & 3\end{array}\right]$$
\begin{aligned}
\therefore \quad m_{11} & =\left|\begin{array}{cc}
4 & -5 \\
-1 & 3
\end{array}\right|=12-5=7 \\
m_{12} & =\left|\begin{array}{cc}
3 & -5 \\
2 & 3
\end{array}\right|=9+10=19 \\
m_{13} & =\left|\begin{array}{cc}
3 & 4 \\
2 & -1
\end{array}\right|=-3-8=-11
\end{aligned}
$
Thus $\quad m_{21}=-1, m_{22}=-1, m_{23}=1$$
\begin{aligned}
m_{31} & =-3, m_{32}=-11, m_{33}=7 \\
Y=\left[m_{i j}\right] & =\left[\begin{array}{lll}
m_{11} & m_{12} & m_{13} \\
m_{21} & m_{22} & m_{23} \\
m_{31} & m_{32} & m_{33}
\end{array}\right]=\left[\begin{array}{ccc}
7 & 19 & -11 \\
-1 & -1 & 1 \\
-3 & -11 & 7
\end{array}\right]
\end{aligned}
$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

If $\displaystyle \text{a}_{\text{ij}}=0\left (\text{i}\neq \text{j} \right )$ and $\displaystyle\text{a}_{\text{ij}}=2\left (\text{i= j} \right )$ then the matrix $\text{A}=\displaystyle \left [ \text{a}_{\text{ij}} \right ]_{\text{n}\times\text{n}}$ ​ is a _______ matrix ?
  1. unit
  2. null
  3. scalar
  4. skew symmetric
The function $\text{f(x)}=\begin{cases}\frac{\text{x}^2}{\text{a}},&0\leq\text{x}<1\\\text{a},&1\leq\text{x}<\sqrt{2}\\\frac{2\text{b}^2-4\text{b}}{\text{x}^2},&\sqrt{2}\leq\text{x}<\infty\end{cases}$ is continuous for $0\leq\text{x}<\infty,$ then the most suitable values of a and b are:
  1. $\text{a}=1,\text{ b}=-1$
  2. $\text{a}=-1,\text{ b}=1+\sqrt{2}$
  3. $\text{a}=-1,\text{ b}=1$
  4. $\text{None os these}.$
The area of the region bounded by the curve $x^2 = 4y$ and the straight line $x = 4y - 2$ is:
$\lim\limits_{\text{n}\rightarrow\infty}\Big\{\frac{1}{2\text{n}+1}+\frac{1}{2\text{n}+2}+\ .....+\frac{1}{2\text{n}+\text{n}}\Big\}$ is equal to:
  1. $\ln\Big(\frac{1}{3}\Big)$
  2. $\ln\Big(\frac{2}{3}\Big)$
  3. $\ln\Big(\frac{3}{2}\Big)$
  4. $\ln\Big(\frac{4}{3}\Big)$
Area bounded by parabola $y^2 = x$ and straight line $2y = x$ is:
Solve for x : $\{\text{x}\cos(\cot^{-1}\text{x})+\sin(\cot^{-1}\text{x})\}^2=\frac{51}{50}$
  1. $\frac{1}{\sqrt{2}}$
  2. $\frac{1}{5\sqrt{2}}$
  3. $2\sqrt{2}$
  4. $5\sqrt{2}$
Find the intervals in which the function $f$ given by $f(x)=x^2-4 x+6$ is strictly increasing.
A straight line L on the xy-plane bisects the angle between OX and OY. What are the direction cosines of L:
  1. $\Big(\frac{1}{\sqrt{2}},\frac{1}{\sqrt{2}},0\Big)$
  2. $\Big(\frac{1}{2},\frac{\sqrt{3}}{2},0\Big)$
  3. $\big(0,0,1\big)$
  4. $\Big(\frac{2}{3},\frac{2}{3},\frac{1}{3}\Big)$
Area bounded by the lines y = |x| - 2 and y = 1 - |x - 1| is equal to:
  1. 4 sq. units
  2. 6 sq. units
  3. 2 sq. units
  4. 8 sq. units
Choose the correct answer from the given four options.
Let $\text{f}:\text{R}-\Big\{\frac{3}{5}\Big\}\rightarrow\ \text{R}$ be defined by $\text{f}(\text{x})=\frac{3\text{x}+2}{5\text{x}-3}.$ Then,
  1. $\text{f}^{-1}(\text{x})=\text{f}(\text{x})$
  2. $\text{f}^{-1}(\text{x})=-\text{f}(\text{x})$
  3. $(\text{fof})\text{x}=-\text{x}$
  4. $\text{f}^{-1}\text{x}=\frac{1}{19}\text{f}(\text{x})$