Question

Calcule o valor do determinante da matriz A abaixo

Answer 1

Resposta

$\boxed{DetA=-9}$

DETERMINANTE DE UMA MATRIZ

$DetA=\left[\begin{array}{ccc}1&3&1\\4&5&2\\8&2&3\end{array}\right]$

$DetA = \left[\begin{array}{ccc}1&3&1\\4&5&2\\8&2&3\end{array}\right] \left[\begin{array}{ccc}1&3\\4&5\\8&2\end{array}\right]$

$DetA = (1.5.3+3.2.8+1.4.2) - (8.5.1+2.2.1+3.4.3)$$DetA = (15+48+8)-(40+4+36)$

$DetA = (71) - (80)$

$DetA = -9$

Veja mais nas tarefas:

https://brainly.com.br/tarefa/5539945

https://brainly.com.br/tarefa/29926752

https://brainly.com.br/tarefa/17339369

Answer 2

$\large\boxed{\begin{array}{l}\sf Para\,calcular\,o\,determinante\,de\,uma\\\sf matriz\,quadrada\,3x3\,deve-se\,repetir\\\sf as\,duas\,primeiras\,colunas\,e\,somar\\\sf o\,produto\,dos\,elementos\,da\,diagonal\\\sf principal\,e\,depois\,subtrair\,a\,soma\,dos\\\sf produtos\,dos\,elementos\,da \,diagonal\\\sf inversa.\end{array}}$

$\large\boxed{\begin{array}{l}\sf Det\,A=\left|\begin{array}{c c c}\sf1&\sf3&\sf1\\\sf4&\sf5&\sf2\\\sf8&\sf2&\sf3\end{array}\right|\left|\begin{array}{c c}\sf1&\sf3\\\sf4&\sf5\\\sf8&\sf2\end{array}\right|\\\\\sf Det\,A=15+48+8-[36+4+40]\\\sf Det\,A=71-[80]\\\sf Det\,A=71-80\\\sf Det\,A=-9\end{array}}$