Compute the determinant of the matrix by cofactor expansion.
-$\left[ \begin{array} { l l l } 3 & 2 & 5 \ 1 & 1 & 4 \ 3 & 3 & 4 \end{array} \right]$
A) $- 56$
B) 110
C) 8
D) $- 8$

Question

Quizplus · Accepted Answer

The determinant can be calculated using cofactor expansion along the first row: $3(1 \cdot 4 - 4 \cdot 3) - 2(1 \cdot 4 - 4 \cdot 3) + 5(1 \cdot 3 - 3 \cdot 1) = 3(-8) - 2(-8) + 5(0) = -24 + 16 = -8$.

Compute the Determinant of the Matrix by Cofactor Expansion [325114334]\left[ \begin{array} { l l l } 3 & 2 & 5 \\ 1 & 1 & 4 \\ 3 & 3 & 4 \end{array} \right]​313​213​544​​

Compute the Determinant of the Matrix by Cofactor Expansion $\left[ \begin{array} { l l l } 3 & 2 & 5 \\ 1 & 1 & 4 \\ 3 & 3 & 4 \end{array} \right]$