$$$\left[\begin{array}{cc}3 & 1\\-7 & 2\end{array}\right]$$$:n determinantti

Laske $$$\left|\begin{array}{cc}3 & 1\\-7 & 2\end{array}\right|$$$.

2x2-matriisin determinantti on $$$\left|\begin{array}{cc}a & b\\c & d\end{array}\right| = a d - b c$$$.

$$$\left|\begin{array}{cc}3 & 1\\-7 & 2\end{array}\right| = \left(3\right)\cdot \left(2\right) - \left(1\right)\cdot \left(-7\right) = 13$$$

$$$\left|\begin{array}{cc}3 & 1\\-7 & 2\end{array}\right| = 13$$$A