1. The problem statement, all variables and given/known data Find the laurent series about z=-2 for: f(z) = 1/(z(z+2)3) 2. Relevant equations 3. The attempt at a solution Setting t = z+2 yields: f(t) = 1/(t3(t-2)) = 1/t (-1/(2(1-t/2))) = (1/t)3 * (-1/2) * Ʃ(t/2)n which can be put together in a sum, but I can't be bothered due to my poor Latex skills. My question is however: In what region will this sum converge? Am I right at saying that the expansion will only be valid in the region described by the circle lz+2l<2? If not please tell me, because the term 1/(t-2) should wreak havoc according to me if we go outside this circle.