Let $\mathbb{C}$ be the D372: Set of complex numbers.
The standard complex sine function is the D4881: Complex function \begin{equation} \sin : \mathbb{C} \to \mathbb{C}, \quad \sin(z) = \sum_{n = 0}^{\infty} (-1)^n \frac{z^{2n + 1}}{(2n + 1)!} \end{equation}