[Kowit Pat.]

ตอบข้อ 3

$|2A^t+BC^2+B^tC| = |\bmatrix{0 & 0 \\ 2 & 2} +\bmatrix{1 & 1 \\ 0 & 0} +\bmatrix{1 & -1 \\ 1 & -1} |$

$|\bmatrix{2 & 0 \\ 3 & 1}| = 2$