For $\alpha, \beta \in R$, suppose the system of linear equations $x-y+z=5$ ; $ 2 x+2 y+\alpha z=8 $ ; $3 x-y+4 z=\beta$ has infinitely many solutions. Then $\alpha$ and $\beta$ are the roots of

If the system of equations, $a^2 x - ay = 1 - a$ & $bx + (3 - 2b) y = 3 + a$ possess a unique solution $x = 1, y = 1$ then :

The number of distinct real roots of $\left|\begin{array}{lll}\sin x & \cos x & \cos x \\ \cos x & \sin x & \cos x \\ \cos x & \cos x & \sin x\end{array}\right|=0$ in the interval $-\frac{\pi}{4} \leq x \leq \frac{\pi}{4}$ is

If $D(x) =$ $\left| {\begin{array}{*{20}{c}}{x - 1}&{{{(x - 1)}^2}}&{{x^3}}\\{x - 1}&{{x^2}}&{{{(x + 1)}^3}}\\x&{{{(x + 1)}^2}}&{{{(x + 1)}^3}}\end{array}} \right|$ then the coefficient of $x$ in $D(x)$ is

Let $a, b, c > 0$ and $\Delta  = \left| \begin{gathered}
  a + b\,\,b\,\,c \hfill \\
  b\, + \,c\,\,c\,\,\,a \hfill \\
  c + a\,\,a\,\,b \hfill \\ 
\end{gathered}  \right| ,$ then which of the following is not correct?

If $A = \left[ {\begin{array}{*{20}{c}}\alpha &2\\2&\alpha \end{array}} \right]$ and $|{A^3}|$=125, then $\alpha = $