I am trying to take the laplace transform of $\mathrm{cos}\left(t\right)u(t-\pi )$ . Is it valid for me to treat it as $((\mathrm{cos}\left(t\right)+\pi )-\pi )u(t-\pi )$ and treat $\mathrm{cos}\left(t\right)-\pi$ as f(t) and use the 2nd shifting property, or is this not the correct procedure?