The Eigenvalues of the Matrix $$A = \left( \begin{array} { l l } 1 & - 2 \\1 & - 1\end{array} \right)$$

Multiple Choice

The eigenvalues of the matrix $$A = \left( \begin{array} { l l } 1 & - 2 \\1 & - 1\end{array} \right)$$ are

A) $\pm \sqrt { 3 }$
B) $\pm \sqrt { 3 } i$
C) $\pm 1$
D) $\pm 2 i$
E) $\pm$