For positive integer $p$, consider the holomorphic function
$f(z)=\frac{\sin (z)}{z^p}$ , for $z\in \mathbb{C}\setminus \{0\}$ .
For which values of $p$ , does there exist a holomorphic function $g:\mathbb{C}\setminus \{0\}\to \mathbb{C}$ such that $g'(z)=f(z)$ for $z\in \mathbb{C}\setminus \{0\}?$
$(1)$ All even integers .
$(2)$ All odd integers.
$(3)$ All multiples of $3$.
$(4)$ All multiples of $4$.
My thinking :- I am aware of the fact "Every analytic function on a simply connected domain has a primitive (anti-derivative)"
Here , the domain is not simply connected and I am not sure how else to proceed.
Please give a hint. Thank you.
Hint: Consider the series expansion of $\sin$. Note that monomial functions of the form $z \mapsto z^n$ have an anti-derivative (on $\Bbb C \setminus \{0\}$) iff $n \neq -1$.
(Convergence issues aside) This tells you that you need to pick a $p$ such that there is no $1/z$ term. After this, show that all such $p$ actually do give a function with an anti-derivative.