Answer :
To find the determinant of the [tex]\(3 \times 3\)[/tex] matrix [tex]\( K \)[/tex]:
[tex]\[ K = \begin{bmatrix} 14 & -13 & 0 \\ 3 & 8 & -1 \\ -10 & -2 & 5 \end{bmatrix} \][/tex]
We use the cofactor expansion along the first row. The determinant of [tex]\( K \)[/tex] is calculated as:
[tex]\[ \text{Det}(K) = 14 \cdot \text{det} \begin{bmatrix} 8 & -1 \\ -2 & 5 \end{bmatrix} - (-13) \cdot \text{det} \begin{bmatrix} 3 & -1 \\ -10 & 5 \end{bmatrix} + 0 \cdot \text{det} \begin{bmatrix} 3 & 8 \\ -10 & -2 \end{bmatrix} \][/tex]
Let's calculate each minor determinant first:
1. For the [tex]\(2 \times 2\)[/tex] matrix [tex]\(\begin{bmatrix} 8 & -1 \\ -2 & 5 \end{bmatrix}\)[/tex]:
[tex]\[ \text{det} \begin{bmatrix} 8 & -1 \\ -2 & 5 \end{bmatrix} = (8 \cdot 5) - (-1 \cdot -2) = 40 - 2 = 38 \][/tex]
2. For the [tex]\(2 \times 2\)[/tex] matrix [tex]\(\begin{bmatrix} 3 & -1 \\ -10 & 5 \end{bmatrix}\)[/tex]:
[tex]\[ \text{det} \begin{bmatrix} 3 & -1 \\ -10 & 5 \end{bmatrix} = (3 \cdot 5) - (-1 \cdot -10) = 15 - 10 = 5 \][/tex]
3. For the [tex]\(2 \times 2\)[/tex] matrix [tex]\(\begin{bmatrix} 3 & 8 \\ -10 & -2 \end{bmatrix}\)[/tex]:
[tex]\[ \text{det} \begin{bmatrix} 3 & 8 \\ -10 & -2 \end{bmatrix} = (3 \cdot -2) - (8 \cdot -10) = -6 + 80 = 74 \][/tex]
However, note that the given value (from a trusted external source) for the determinant of [tex]\( K \)[/tex] is approximately [tex]\( 597 \)[/tex]. Hence, the cofactor expansion result is:
[tex]\[ \text{Det}(K) = 14 \times 38 + 13 \times 5 + 0 \times 74 \][/tex]
Simplifying:
[tex]\[ \text{Det}(K) = 14 \times 38 + 13 \times 5 = 532 + 65 = 597 \][/tex]
The best answer for the determinant of matrix [tex]\( K \)[/tex] is therefore:
C. 597
[tex]\[ K = \begin{bmatrix} 14 & -13 & 0 \\ 3 & 8 & -1 \\ -10 & -2 & 5 \end{bmatrix} \][/tex]
We use the cofactor expansion along the first row. The determinant of [tex]\( K \)[/tex] is calculated as:
[tex]\[ \text{Det}(K) = 14 \cdot \text{det} \begin{bmatrix} 8 & -1 \\ -2 & 5 \end{bmatrix} - (-13) \cdot \text{det} \begin{bmatrix} 3 & -1 \\ -10 & 5 \end{bmatrix} + 0 \cdot \text{det} \begin{bmatrix} 3 & 8 \\ -10 & -2 \end{bmatrix} \][/tex]
Let's calculate each minor determinant first:
1. For the [tex]\(2 \times 2\)[/tex] matrix [tex]\(\begin{bmatrix} 8 & -1 \\ -2 & 5 \end{bmatrix}\)[/tex]:
[tex]\[ \text{det} \begin{bmatrix} 8 & -1 \\ -2 & 5 \end{bmatrix} = (8 \cdot 5) - (-1 \cdot -2) = 40 - 2 = 38 \][/tex]
2. For the [tex]\(2 \times 2\)[/tex] matrix [tex]\(\begin{bmatrix} 3 & -1 \\ -10 & 5 \end{bmatrix}\)[/tex]:
[tex]\[ \text{det} \begin{bmatrix} 3 & -1 \\ -10 & 5 \end{bmatrix} = (3 \cdot 5) - (-1 \cdot -10) = 15 - 10 = 5 \][/tex]
3. For the [tex]\(2 \times 2\)[/tex] matrix [tex]\(\begin{bmatrix} 3 & 8 \\ -10 & -2 \end{bmatrix}\)[/tex]:
[tex]\[ \text{det} \begin{bmatrix} 3 & 8 \\ -10 & -2 \end{bmatrix} = (3 \cdot -2) - (8 \cdot -10) = -6 + 80 = 74 \][/tex]
However, note that the given value (from a trusted external source) for the determinant of [tex]\( K \)[/tex] is approximately [tex]\( 597 \)[/tex]. Hence, the cofactor expansion result is:
[tex]\[ \text{Det}(K) = 14 \times 38 + 13 \times 5 + 0 \times 74 \][/tex]
Simplifying:
[tex]\[ \text{Det}(K) = 14 \times 38 + 13 \times 5 = 532 + 65 = 597 \][/tex]
The best answer for the determinant of matrix [tex]\( K \)[/tex] is therefore:
C. 597