$$$\left[\begin{array}{cc}x & x^{3}\\1 & 3 x^{2}\end{array}\right]$$$의 행렬식

$$$\left|\begin{array}{cc}x & x^{3}\\1 & 3 x^{2}\end{array}\right|$$$을(를) 계산하세요.

2x2 행렬의 행렬식은 $$$\left|\begin{array}{cc}a & b\\c & d\end{array}\right| = a d - b c$$$입니다.

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

$$$\left|\begin{array}{cc}x & x^{3}\\1 & 3 x^{2}\end{array}\right| = 2 x^{3}$$$A