Lagrange

rewrite in lagrange form find f,g, h find auzxillary equations general solution find particular solution from X(0)=n evaluate the particular solution for some t and values of birth/death or immigration rate

evaluate a pure death process find P(X(t)=0) find median time to extinction

for simple-birth process find Wn = T + T +T E[W] V{W]

incredibly cheeky limit of t->infinity