Question:
Find the determinant of the following matrices.
Difficulty: Easy
Solution:
(i) A = $\left[ \begin{matrix} -1 & 1 \\ 2 & 0 \\ \end{matrix} \right]$
Determinant of matrix A is calculated as:
det A = $\left| \text{A} \right|$
= $\left| \begin{matrix} -1 & 1 \\ 2 & 0 \\ \end{matrix} \right|$
= $\left( -1 \right)\times 0-2\times 1$
= $0-2$
= $-2$
Therefore,
$\left| \text{A} \right|$ = $-2$
(ii) B = $\left[ \begin{matrix} 1 & 3 \\ 2 & -2 \\ \end{matrix} \right]$
Determinant of matrix B is calculated as:
det B = $\left| \text{B} \right|$
= $\left| \begin{matrix} 1 & 3 \\ 2 & -2 \\ \end{matrix} \right|$
= $1\times \left( -2 \right)-3\times 2$
= $-2-6$
= $-8$
Therefore,
$\left| \text{B} \right|$ = $-8$
(iii) C = $\left[ \begin{matrix} 3 & 2 \\ 3 & 2 \\ \end{matrix} \right]$
Determinant of matrix C is calculated as:
det C = $\left| \text{C} \right|$
= $\left| \begin{matrix} 3 & 2 \\ 3 & 2 \\ \end{matrix} \right|$
= $3 \times 2 - 2 \times 3$
= $6 - 6$
Therefore, $\left| \text{C} \right|$ = $0$
(iv) D = $\left[ \begin{matrix} 3 & 2 \\ 1 & 4 \\ \end{matrix} \right]$
Determinant of matrix D is calculated as:
det D = $\left| \text{D} \right|$
= $\left| \begin{matrix} 3 & 2 \\ 1 & 4 \\ \end{matrix} \right|$
= $3 \times 4 - 2 \times 1$
= $12 - 2$
Therefore,
$\left| \text{D} \right|$ = $10$
Sponsored Ads