If $\left| {\begin{array}{*{20}{c}}
  {\cos 2x}&{{{\sin }^2}x}&{\cos 4x} \\ 
  {{{\sin }^2}x}&{\cos 2x}&{{{\cos }^2}x} \\ 
  {\cos 4x}&{{{\cos }^2}x}&{\cos 2x} 
\end{array}} \right| = {a_0} + {a_1}\sin x + {a_2}{\sin ^2}x + .....$ then $a_0$ is equal to

If the system of linear equations  $x-2 y+z=-4 $   ;  $2 x+\alpha y+3 z=5 $  ;  $3 x-y+\beta z=3$ has infinitely many solutions, then $12 \alpha+13 \beta$ is equal to

If $\left| {\,\begin{array}{*{20}{c}}a&b&{a\alpha - b}\\b&c&{b\alpha - c}\\2&1&0\end{array}\,} \right| = 0$ and $\alpha \ne \frac{1}{2},$ then

if $\left| \begin{gathered}
   - 6\ \ \,\,1\ \ \,\,\lambda \ \  \hfill \\
  \,0\ \ \,\,\,\,3\ \ \,\,7\ \  \hfill \\
   - 1\ \ \,\,0\ \ \,\,5\ \  \hfill \\ 
\end{gathered}  \right| = 5948 $, then $\lambda $  is

The number of values of $\alpha$ for which the system of equations:   $x+y+z=\alpha$ ;  $\alpha x+2 \alpha y+3 z=-1$ ;  $x+3 \alpha y+5 z=4$    is inconsistent, is

If $a,b,c$ be positive and not all equal, then the value of the determinant $\left| {\,\begin{array}{*{20}{c}}a&b&c\\b&c&a\\c&a&b\end{array}\,} \right|$ is