(AR(2): stationarity and Yule–Walker)

For $X_t = 1.2X_{t-1} - 0.35X_{t-2} + e_t$: (a) Find the roots of $\Phi(z)$ and the eigenvalues of the companion matrix, and decide stationarity. (b) Use Yule–Walker to find $\rho_1$ and $\rho_2$. (c) Find the population one-step $R^2$. Which kind of market series might plausibly look like this, and which certainly would not?