Let $D \subset \mathbb{C}$ be a open subset of the complex plane
Let $f: D \to \mathbb{C}$ be a holomorphic function
Let $\{z_n\}_{n \in \mathbb{N}} \subset D$ be a sequence in $D$ such that $z_n \to s \in D$ and we have $f(z_n) \to f(s)=0$
My question is: Is there a subsequence $\{z_{n_k}\}_{k \in \mathbb{N}}$ such that $\forall k \in \mathbb{N}: \Im(f(z_{n_k})) \neq 0$
Thanks.
Well... Not necessarily. Let $f(z)=z$ and $z_n=1/n$ for example.