If \(a_1, a_2, a_3, \ldots, a_n, \ldots\) are in GP, then \(\Delta = \begin{vmatrix} \log a_n & \log(a_n r) & \log(a_n r^2) \\ \log(a_n r^3) & \log(a_n r^4) & \log(a_n r^5) \\ \log(a_n r^6) & \log(a_n r^7) & \log(a_n r^8) \end{vmatrix}\) equals:
Let for \(i = 1, 2, 3\), \(p_i(x)\) be a polynomial of degree 2 in \(x\), \(p_i'(x)\) and \(p_i''(x)\) be the first and second order derivatives of \(p_i(x)\) respectively. Let,\[A(x) = \begin{bmatrix} p_1(x) & p_1'(x) & p_1''(x) \\ p_2(x) & p_2'(x) & p_2''(x) \\ p_3(x) & p_3'(x) & p_3''(x) \end{bmatrix}\]and \(B(x) = [A(x)]^T A(x)\). Then determinant of \(B(x)\)
$A = \begin{bmatrix} \frac{1}{2}[x] & |\sin y| \\ \cos z & 1 \end{bmatrix}$, $B = \begin{bmatrix} [x] & [y] \\ [z] & 1 \end{bmatrix}$ if $x \in [-2, 2]$, $y, z \in (-\pi, \pi)$ if number of triplets $(x, y, z)$ such that $A = B$ is $k$, then value of $k/7$ is _____.
If $a_i^2 + b_i^2 + c_i^2 = 1, (i = 1, 2, 3)$ and $a_i a_j + b_i b_j + c_i c_j = 0$ ($i \neq j; i, j = 1, 2, 3$) then the value of $$\begin{vmatrix} a_1 & a_2 & a_3 \\ b_1 & b_2 & b_3 \\ c_1 & c_2 & c_3 \end{vmatrix}$$ is ____