The mathematical model of a nonlinear system is provided. Using the procedure outlined in this section, find the operating point and derive the linearized model.

\(\begin{cases}\dot{x}_{1}=-x_{1}+3 x_{2}^{3} & x_{1}(0)=0 \\ \dot{x}_{2}=x_{1}+24+\frac{1}{3} e^{-t / 3}, & x_{2}(0)=1\end{cases}\)