The value of $\left| {\,\begin{array}{*{20}{c}}1&{\cos (\beta - \alpha )}&{\cos (\gamma - \alpha )}\\{\cos (\alpha - \beta )}&1&{\cos (\gamma - \beta )}\\{\cos (\alpha - \gamma )}&{\cos (\beta - \gamma )}&1\end{array}} \right|$ is
${\left| {\,\begin{array}{*{20}{c}}{\cos \alpha }&{\sin \alpha }&1\\{\cos \beta }&{\sin \beta }&1\\{\cos \gamma }&{\sin \gamma }&1\end{array}\,} \right|^2}$
${\left| {\,\begin{array}{*{20}{c}}{\sin \alpha }&{\cos \alpha }&0\\{\sin \beta }&{\cos \beta }&0\\{\sin \gamma }&{\cos \gamma }&0\end{array}\,} \right|^2}$
${\left| {\,\begin{array}{*{20}{c}}{\cos \alpha }&{\sin \alpha }&0\\{\sin \beta }&0&{\cos \beta }\\0&{\cos \gamma }&{\sin \gamma }\end{array}\,} \right|^2}$
None of these
If the system of equations
$ 2 x+7 y+\lambda z=3 $
$ 3 x+2 y+5 z=4 $
$ x+\mu y+32 z=-1$
has infinitely many solutions, then $(\lambda-\mu)$ is equal to $\qquad$
If $'a'$ is non real complex number for which system of equations $ax -a^2y + a^3z$ = $0$ , $-a^2x + a^3y + az$ = $0$ and $a^3x + ay -a^2z$ = $0$ has non trivial solutions, then $|a|$ is
${x_1} + 2{x_2} + 3{x_3} = a2{x_1} + 3{x_2} + {x_3} = $ $b3{x_1} + {x_2} + 2{x_3} = c$ this system of equations has
If $A$, $B$ and $C$ are square matrices of order $3$ such that $A = \left[ {\begin{array}{*{20}{c}} x&0&1 \\ 0&y&0 \\ 0&0&z \end{array}} \right]$ and $\left| B \right| = 36$, $\left| C \right| = 4$, $\left( {x,y,z \in N} \right)$ and $\left| {ABC} \right| = 1152$ then the minimum value of $x + y + z$ is
If the system of equation $3x - 2y + z = 0$, $\lambda x - 14y + 15z = 0$, $x + 2y + 3z = 0$ have a non-trivial solution, then $\lambda = $