Question

1) Calcule o Determinante (Det) em cada caso:


a)A= $\left[\begin{array}{ccc}1&3\\2&-1\end{array}\right]$

b)A= $\left[\begin{array}{ccc}1&3&0\\2&5&1\\2&1&3\end{array}\right]$

Answer 1

a)

$A=\left[\begin{array}{cc}1&3\\2&-1\end{array}\right]$

$\det{A}=(1)(-1)-(3)(2)=-1-6\ \therefore$

$\boxed{\det{A}=-7}$

b)

$B=\left[\begin{array}{ccc}1&3&0\\2&5&1\\2&1&3\end{array}\right]$

$\det{B}=(1)(5)(3)+(3)(1)(2)-(3)(2)(3)-(1)(1)(1)\ \therefore$

$\det{B}=15+6-18-1=21-19\ \therefore$

$\boxed{\det{B}=2}$