The value of $\left| \begin{array}{ccc} 1 & x & y \\ 2 & \sin x + 2x & \sin y + 2y \\ 3 & \cos x + 3x & \cos y + 3y \end{array} \right|$ is

The value of $\left| {\begin{array}{*{20}{c}} {{(b + c)}^2} & {{a^2}} & {{a^2}} \\ {{b^2}} & {{(a + c)}^2} & {{b^2}} \\ {{c^2}} & {{c^2}} & {{(a + b)}^2} \end{array}} \right|$ is equal to

If $\left| {\begin{array}{*{20}{c}}{{{(b + c)}^2}}&{{a^2}}&{{a^2}}\\{{b^2}}&{{{(c + a)}^2}}&{{b^2}}\\{{c^2}}&{{c^2}}&{{{(a + b)}^2}}\end{array}} \right| = k\,abc{(a + b + c)^3}$,then the value of $k$ is

$\left| {\begin{array}{*{20}{c}}{a + b}&{a + 2b}&{a + 3b}\\{a + 2b}&{a + 3b}&{a + 4b}\\{a + 4b}&{a + 5b}&{a + 6b}\end{array}} \right| = $

If $a, b$ and $c$ are non-zero numbers,then $\Delta = \left| \begin{array}{ccc} b^2c^2 & bc & b+c \\ c^2a^2 & ca & c+a \\ a^2b^2 & ab & a+b \end{array} \right|$ is equal to

By using properties of determinants,show that:
$\left|\begin{array}{ccc}a^{2}+1 & a b & a c \\ a b & b^{2}+1 & b c \\ c a & c b & c^{2}+1\end{array}\right|=1+a^{2}+b^{2}+c^{2}$