$$$\left[\begin{array}{cc}3 t^{2} & 1\\6 t & 0\end{array}\right]$$$ 的行列式

计算 $$$\left|\begin{array}{cc}3 t^{2} & 1\\6 t & 0\end{array}\right|$$$。

2x2 矩阵的行列式为 $$$\left|\begin{array}{cc}a & b\\c & d\end{array}\right| = a d - b c$$$。

$$$\left|\begin{array}{cc}3 t^{2} & 1\\6 t & 0\end{array}\right| = \left(3 t^{2}\right)\cdot \left(0\right) - \left(1\right)\cdot \left(6 t\right) = - 6 t$$$

$$$\left|\begin{array}{cc}3 t^{2} & 1\\6 t & 0\end{array}\right| = - 6 t$$$A