Question

construa uma matriz 2x3 onde se i=j o valor será 1, se ij o valor será -1​

Answer 1

$\Large\boxed{\begin{array}{l}\sf A=(a_{ij})_{2\times3},a_{ij}=\begin{cases}\sf 1,~~se\,i=j\\\sf -1,~~se\,i\ne j\end{cases}\\\sf a_{11}=1~~a_{12}=-1~~a_{13}=-1\\\sf a_{21}=-1~~a_{22}=1~~a_{23}=-1\\\\\Large\sf A=\begin{bmatrix}\sf1&\sf-1&\sf-1\\\sf-1&\sf1&\sf-1\end{bmatrix}\end{array}}$