A = [tex]\left[\begin{array}{ccc}1&1\\1&0\end{array}\right][/tex]
A² = [tex]\left[\begin{array}{ccc}1&1\\1&0\end{array}\right][/tex] · [tex]\left[\begin{array}{ccc}1&1\\1&0\end{array}\right][/tex] =
( Pentru a înțelege mai ușor )
a₁₁ = 1 · 1 + 1 · 1 = 2
a₁₂ = 1 · 1 + 1 · 0 = 1
a₂₁ = 1 · 1 + 0 · 1 = 1
a₂₂ = 1 · 1 + 0 · 0 = 1
Deci o să avem:
A² = [tex]\left[\begin{array}{ccc}2&1\\1&1\end{array}\right][/tex]
A² - A = [tex]\left[\begin{array}{ccc}2&1\\1&1\end{array}\right][/tex] - [tex]\left[\begin{array}{ccc}1&1\\1&0\end{array}\right][/tex] = [tex]\left[\begin{array}{ccc}1&0\\0&1\end{array}\right][/tex]
