Question

indetifique os elementos a11 a22 a13 na matriz
4 1 -3
9 8 -4
4 5 2

Answer 1

$\left[\begin{array}{ccc}4&1&-3\\9&8&-4\\4&5&2\end{array}\right] =M$
Uma matriz é:
$A_{ij}= \left[\begin{array}{ccc}a_{11}&a_{12}&a_{13}\\a_{21}&a_{22}&a_{23}\\a_{31}&a_{32}&a_{33}\end{array}\right]$
i = linha
j = coluna, sendo assim o elemento $a_{11}$ está na primeira linha da primeira coluna:
$M=\left[\begin{array}{ccc}\underbrace{4}&1&-3\\9&8&-4\\4&5&2\end{array}\right]=\left[\begin{array}{ccc}\underbrace{a_{11}}&a_{12}&a_{13}\\a_{21}&a_{22}&a_{23}\\a_{31}&a_{32}&a_{33}\end{array}\right]=4=a_{11}$
Seguindo o racínio descrito acima, podemos encontrar todos:
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \underbrace{a_{11}=4\ \ \ \ \ \ \ a_{22}=8\ \ \ \ \ \ a_{13}=-3}\\ \\ M=\left[\begin{array}{ccc}\underbrace{4}&1&\underbrace{-3}\\9&\underbrace{8}&-4\\4&5&2\end{array}\right]=\left[\begin{array}{ccc}\underbrace{a_{11}}&a_{12}&\underbrace{a_{13}}\\a_{21}&\underbrace{a_{22}}&a_{23}\\a_{31}&a_{32}&a_{33}\end{array}\right]$