Question

Sabendo que A . A = A² e que A = [2 -1] [-3 1], Calcule A².

A = [2 -1] (2x2)
      [-3 1]

Answer 1

$\left[\begin{array}{ccc}2&-1\\-3&1\\\end{array}\right] * \left[\begin{array}{ccc}2&-1\\-3&1\\\end{array}\right]= \left[\begin{array}{ccc}4+3&-2-1\\-6-3&3+1\\\end{array}\right] = \left[\begin{array}{ccc}7&-3\\-9&4\\\end{array}\right]$