A continuous-time Markov Chain has generator matrix,
$$ Q = \begin{pmatrix} -1 & 1 & 0 \\ 1 & -2 & 1 \\ 2 & 2 & -4 \\ \end{pmatrix} $$
(i) Exhibit the transition matrix of the embedded Markov chain.
(ii) Exhibit the holding time parameter for each state.
I'm struggling to understand a lot of the methods and was hoping someone could show me how this works/walk me through it? I assume I need to start with making sure $Q$ is diagonalizable but I'm not really sure how to express the following;
$P(t) = e^{tQ} = Se^{tD}S^{-1}$
But I've never seen a matrix be in the exponential.. I know $D$ is the diagonal of of eigenvalues but I don't know how to express $e^{tD}$. Thank you in advance for your help!