the original system is $$\begin{cases}\dot{x} = y +\cos t \\ \dot{y} = 1 -x\end{cases}$$
it does not look like homogeneous one, so I do not know how to proceed with it. I have never worked wit it.
as for homogeneous I know that we have to:
1.) write down the matrix from the given system
2.) find its eigenvalues and therefore eigenvectors/ generalized eigenvectors
3.) write diwn the answer
is there big difference between homogeneous and non-homogeneous systems in solving proccess? And I am also confused about $\cos t$ a lot