# Region of Convergence and Inverse Laplace

#### dwsmith

##### Well-known member
How do I find all the possible ROC for a transfer function written as
$H(s) = \frac{(s - 2)^{n_1}}{(s + 2)^{n_2}(s + 1)^{n_3}(s - 1)^{n_4}}$
where $$n_i\in\mathbb{N}$$.