The determinant of a matrix is a special number that can be calculated from its elements. It tells us important information about the matrix, such as whether the matrix is invertible or singular. If the determinant is zero, the matrix is singular and does not have an inverse. If it's not zero, the matrix is invertible.
For triangular matrices, calculating the determinant becomes a simpler task. A triangular matrix is a type where all elements above or below the main diagonal are zero. In our case, the matrix given is upper triangular. Calculating the determinant of a triangular matrix requires multiplying all the diagonal elements together.
So for the matrix \(A\) given, we have:
- Diagonal elements: 2, 2, 2
Multiply these together to find the determinant:
- \( ext{det}(A) = 2 \times 2 \times 2 = 8 \)
This shows us that the determinant is not zero, indicating that the matrix is invertible.