Question

determine a matriz A=(aij)2x2, tal que :

Answer 1

$\left[\begin{array}{ccc}aij&aij&\\aij&aij&\\\end{array}\right]$

$\left[\begin{array}{cc}a11&a12&\\a21&a22&\\\end{array}\right]$

já que 1 se i=j  e -1 se i≠j

$\left[\begin{array}{cc}1&-1&\\-1&1&\\\end{array}\right]$