Find the state vector via the formal-solution approach. (dot{mathbf{x}}=left[begin{array}{cc}1 & -1 -4 & 1end{array} ight] mathbf{x}+left[begin{array}{c}1

Find the state vector via the formal-solution approach.

\(\dot{\mathbf{x}}=\left[\begin{array}{cc}1 & -1 \\ -4 & 1\end{array}\right] \mathbf{x}+\left[\begin{array}{c}1 \\ \frac{1}{2}\end{array}\right] u, \quad u=\) unit-step, \(\mathbf{x}(0)=\left\{\begin{array}{c}-1 \\ 0\end{array}\right\}\)