$$$\left[\begin{array}{cc}1 & 2\\4 & 5\end{array}\right]$$$:n determinantti

Laske $$$\left|\begin{array}{cc}1 & 2\\4 & 5\end{array}\right|$$$.

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

$$$\left|\begin{array}{cc}1 & 2\\4 & 5\end{array}\right| = \left(1\right)\cdot \left(5\right) - \left(2\right)\cdot \left(4\right) = -3$$$

$$$\left|\begin{array}{cc}1 & 2\\4 & 5\end{array}\right| = -3$$$A