જો $A=\left[\begin{array}{lll}1 & 1 & -2 \\ 2 & 1 & -3 \\ 5 & 4 & -9\end{array}\right]$ હોય, તો $|A|$ શોધો.
જો $A=\left[\begin{array}{lll}1 & 1 & -2 \\ 2 & 1 & -3 \\ 5 & 4 & -9\end{array}\right]$ હોય, તો $|A|$ શોધો.
Let $A=\left[\begin{array}{lll}1 & 1 & -2 \\ 2 & 1 & -3 \\ 5 & 4 & -9\end{array}\right]$
By expanding along the first row, we have:
$A=\left[\begin{array}{lll}1 & 1 & -2 \\ 2 & 1 & -3 \\ 5 & 4 & -9\end{array}\right]$
$|A|=1\left|\begin{array}{cc}1 & -3 \\ 4 & -9\end{array}\right|-1\left|\begin{array}{cc}2 & -3 \\ 5 & -9\end{array}\right|-2\left|\begin{array}{cc}2 & 1 \\ 5 & 4\end{array}\right|$
$=1(-9+12)-1(-18+15)-2(8-5)$
$=1(3)-1(-3)-2(3)$
$=3+3-6$
$=6-6$
$=0$
Similar Questions
$\mathrm{A}$ એ $3 \times 3$ કક્ષાનો ચોરસ શ્રેણિક હોય, તો $|\mathrm{k A}|$ $=$ ........
$\mathrm{A}$ એ $3 \times 3$ કક્ષાનો ચોરસ શ્રેણિક હોય, તો $|\mathrm{k A}|$ $=$ ........
જો $\left| \begin{gathered}
- 6\ \ \,\,1\ \ \,\,\lambda \ \ \hfill \\
\,0\ \ \,\,\,\,3\ \ \,\,7\ \ \hfill \\
- 1\ \ \,\,0\ \ \,\,5\ \ \hfill \\
\end{gathered} \right| = 5948 $, તો $\lambda $ મેળવો.
જો $\left| \begin{gathered}
- 6\ \ \,\,1\ \ \,\,\lambda \ \ \hfill \\
\,0\ \ \,\,\,\,3\ \ \,\,7\ \ \hfill \\
- 1\ \ \,\,0\ \ \,\,5\ \ \hfill \\
\end{gathered} \right| = 5948 $, તો $\lambda $ મેળવો.
$\left| {\,\begin{array}{*{20}{c}}{11}&{12}&{13}\\{12}&{13}&{14}\\{13}&{14}&{15}\end{array}\,} \right| = $
$\left| {\,\begin{array}{*{20}{c}}{11}&{12}&{13}\\{12}&{13}&{14}\\{13}&{14}&{15}\end{array}\,} \right| = $
જો રેખાઓની સંહતિ $x+ ay+z\,= 3$ ; $x + 2y+ 2z\, = 6$ ; $x+5y+ 3z\, = b$ ને એકપણ ઉકેલ શકય ન હોય તો . . .
જો રેખાઓની સંહતિ $x+ ay+z\,= 3$ ; $x + 2y+ 2z\, = 6$ ; $x+5y+ 3z\, = b$ ને એકપણ ઉકેલ શકય ન હોય તો . . .
- [JEE MAIN 2018]
જો ${\Delta _r} = \left| {\begin{array}{*{20}{c}}
r&{2r - 1}&{3r - 2} \\
{\frac{n}{2}}&{n - 1}&a \\
{\frac{1}{2}n\left( {n - 1} \right)}&{{{\left( {n - 1} \right)}^2}}&{\frac{1}{2}\left( {n - 1} \right)\left( {3n - 4} \right)}
\end{array}} \right|$ તો $\sum\limits_{r = 1}^{n - 1} {{\Delta _r}} $ ની કિમત . . .
જો ${\Delta _r} = \left| {\begin{array}{*{20}{c}}
r&{2r - 1}&{3r - 2} \\
{\frac{n}{2}}&{n - 1}&a \\
{\frac{1}{2}n\left( {n - 1} \right)}&{{{\left( {n - 1} \right)}^2}}&{\frac{1}{2}\left( {n - 1} \right)\left( {3n - 4} \right)}
\end{array}} \right|$ તો $\sum\limits_{r = 1}^{n - 1} {{\Delta _r}} $ ની કિમત . . .
- [JEE MAIN 2014]