The Characteristic Equation Of $A = \left( \begin{array} { c c } 2 & - 1 \\- 1 & 2\end{array} \right)$

Multiple Choice

The characteristic equation of $A = \left( \begin{array} { c c } 2 & - 1 \\- 1 & 2\end{array} \right)$ is

A) $\lambda ^ { 2 } - 1 = 0$
B) $\lambda ^ { 2 } + 4 \lambda + 5 = 0$
C) $\lambda ^ { 2 } - 4 \lambda + 5 = 0$
D) $\lambda ^ { 2 } + 4 \lambda + 3 = 0$
E) $\lambda ^ { 2 } - 4 \lambda + 3 = 0$