We are given the equation \(A + B = \begin{bmatrix} 4 & 1 & 4 \\ 1 & 4 & 4 \end{bmatrix}\) and the matrix \(B = \begin{bmatrix} 1 & 0 & -2 \\ -1 & 3 & 0 \end{bmatrix}\). We need to find matrix \( A \).
To solve for \( A \), we subtract matrix \( B \) from both sides of the equation:
\(A = \begin{bmatrix} 4 & 1 & 4 \\ 1 & 4 & 4 \end{bmatrix} - \begin{bmatrix} 1 & 0 & -2 \\ -1 & 3 & 0 \end{bmatrix}\)
Subtracting corresponding elements of the matrices:
\(A = \begin{bmatrix} 4-1 & 1-0 & 4 - (-2) \\ 1 - (-1) & 4 - 3 & 4 - 0 \end{bmatrix}\)
\(A = \begin{bmatrix} 3 & 1 & 6 \\ 2 & 1 & 4 \end{bmatrix}\)
The matrix \( A \) is \( \begin{bmatrix} 3 & 1 & 6 \\ 2 & 1 & 4 \end{bmatrix} \).
Let $A = \begin{bmatrix} \cos \theta & 0 & -\sin \theta \\ 0 & 1 & 0 \\ \sin \theta & 0 & \cos \theta \end{bmatrix}$. If for some $\theta \in (0, \pi)$, $A^2 = A^T$, then the sum of the diagonal elements of the matrix $(A + I)^3 + (A - I)^3 - 6A$ is equal to
Let $ A $ be a $ 3 \times 3 $ matrix such that $ | \text{adj} (\text{adj} A) | = 81.
$ If $ S = \left\{ n \in \mathbb{Z}: \left| \text{adj} (\text{adj} A) \right|^{\frac{(n - 1)^2}{2}} = |A|^{(3n^2 - 5n - 4)} \right\}, $ then the value of $ \sum_{n \in S} |A| (n^2 + n) $ is:
Let \( A = \begin{bmatrix} \alpha & -1 \\ 6 & \beta \end{bmatrix} , \ \alpha > 0 \), such that \( \det(A) = 0 \) and \( \alpha + \beta = 1. \) If \( I \) denotes the \( 2 \times 2 \) identity matrix, then the matrix \( (I + A)^8 \) is: