For $\alpha, \beta \in R$ and a natural number $n$,let $A_r = \begin{vmatrix} r & 1 & \frac{n^2}{2} + \alpha \\ 2r & 2 & n^2 - \beta \\ 3r - 2 & 3 & \frac{n(3n - 1)}{2} \end{vmatrix}$. Then $2A_{10} - A_8$ is equal to:

Let $\omega$ be a complex number such that $2\omega + 1 = z$ where $z = \sqrt{-3}$. If $\left| \begin{array}{ccc} 1 & 1 & 1 \\ 1 & -\omega^2 - 1 & \omega^2 \\ 1 & \omega^2 & \omega^7 \end{array} \right| = 3k$,then $k$ is equal to:

Let $M=\begin{bmatrix} \sin^4 \theta & -1-\sin^2 \theta \\ 1+\cos^2 \theta & \cos^4 \theta \end{bmatrix} = \alpha I + \beta M^{-1}$,where $\alpha = \alpha(\theta)$ and $\beta = \beta(\theta)$ are real numbers,and $I$ is the $2 \times 2$ identity matrix. If $\alpha^*$ is the minimum of the set $\{\alpha(\theta) : \theta \in [0, 2\pi)\}$ and $\beta^*$ is the minimum of the set $\{\beta(\theta) : \theta \in [0, 2\pi)\}$,then the value of $\alpha^* + \beta^*$ is

Let $S=\{n \in N \mid \begin{bmatrix} 0 & i \\ 1 & 0 \end{bmatrix}^{n} \begin{bmatrix} a & b \\ c & d \end{bmatrix} = \begin{bmatrix} a & b \\ c & d \end{bmatrix} \forall a, b, c, d \in R \}$,where $i=\sqrt{-1}$. Then the number of $2$-digit numbers in the set $S$ is $......$

For a square matrix $B$ of order $3$,if $B^T=B^{-1}$ and $|B|=1$,then $|B-I|=$

If $D_1$ and $D_2$ are two $3 \times 3$ diagonal matrices,then