If a meromorphic function has a single pole of order $N$ at $z_0$, then is the principal part of that function always
$$\frac{c}{(z-z_0)^N}$$ for some constant $c$? A counterexample or proof would be really helpful. Thanks.
If a meromorphic function has a single pole of order $N$ at $z_0$, then is the principal part of that function always
$$\frac{c}{(z-z_0)^N}$$ for some constant $c$? A counterexample or proof would be really helpful. Thanks.
No, of course not. Take$$\frac1{z^2}+\frac1z\tag1$$(with domain equal to $\mathbb{C}\setminus\{0\}$) for instance. The principal part of this function is $(1)$.