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Let $$A = \begin{pmatrix} 0 & 0 & -1 \\ 0 & -1 & 0 \\ -1 & 0 & 0 \end{pmatrix}$$. The only correct statement about the matrix $$A$$ is
We are given the matrix:
$$ A = \begin{pmatrix} 0 & 0 & -1 \\ 0 & -1 & 0 \\ -1 & 0 & 0 \end{pmatrix} $$
Let us evaluate the characteristic behavior and properties of this matrix by finding its square, $$ A^2 $$.
Step 1: Matrix Multiplication
To find $$ A^2 $$, we multiply the matrix $$ A $$ by itself:
$$ A^2 = \begin{pmatrix} 0 & 0 & -1 \\ 0 & -1 & 0 \\ -1 & 0 & 0 \end{pmatrix} \begin{pmatrix} 0 & 0 & -1 \\ 0 & -1 & 0 \\ -1 & 0 & 0 \end{pmatrix} $$
Step 2: Calculating Row by Column Elements
Row 1, Column 1:
$$ (0)(0) + (0)(0) + (-1)(-1) = 1 $$
Row 1, Column 2:
$$ (0)(0) + (0)(-1) + (-1)(0) = 0 $$
Row 1, Column 3:
$$ (0)(-1) + (0)(0) + (-1)(0) = 0 $$
Row 2, Column 1:
$$ (0)(0) + (-1)(0) + (0)(-1) = 0 $$
Row 2, Column 2:
$$ (0)(0) + (-1)(-1) + (0)(0) = 1 $$
Row 2, Column 3:
$$ (0)(-1) + (-1)(0) + (0)(0) = 0 $$
Row 3, Column 1:
$$ (-1)(0) + (0)(0) + (0)(-1) = 0 $$
Row 3, Column 2:
$$ (-1)(0) + (0)(-1) + (0)(0) = 0 $$
Row 3, Column 3:
$$ (-1)(-1) + (0)(0) + (0)(0) = 1 $$
Step 3: Conclusion
Combining all calculated elements yields the Identity matrix:
$$ A^2 = \begin{pmatrix} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{pmatrix} = I $$
A matrix whose square equals the identity matrix is called an involutory matrix. Since $$ A^2 = I $$, it also implies that the matrix is its own inverse, meaning $$ A = A^{-1} $$.
Therefore, the only correct statement about the matrix $$ A $$ is that $$ A^2 = I $$ (or that $$ A $$ is an involutory matrix).
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