A linear time-invariant system is described by the state variable model
\[
\left[\begin{array}{l}
x_{1} \\
x_{2}
\end{array}\right]=\left[\begin{array}{rc}
-1 & 0 \\
0 & -2
\end{array}\right]\left[\begin{array}{l}
x_{1} \\
x_{2}
\end{array}\right]+\left[\begin{array}{l}
0 \\
1
\end{array}\right] u=\left[\begin{array}{ll}
1 & 2
\end{array}\right]\left[\begin{array}{l}
x_{1} \\
x_{2}
\end{array}\right]
\]
- The system is completely controllable
- The system is not completely controllable
- The system is completely observable
- The system is not completely observable.