[tex] A^{2} = \left[\begin{array}{ccc}1&0\\0&1\end{array}\right] = I_{2} [/tex]
[tex] A^{3}= A^{2} x A= \left[\begin{array}{ccc}-1&0\\0&-1\end{array}\right] =A[/tex]
[tex] A^{4}= A^{3} x A= \left[\begin{array}{ccc}1&0\\0&1\end{array}\right]= I_{2} [/tex]
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[tex] A^{2010} = (A^{2})^{1005}= ( I_{2} )^{1005}= I_{2} [/tex]
