Unnormalized sinc function
= Unnormalized sinc function
{title2=$\operatorname{sinc}(z)=\sum_{m\geq0}\frac{(-1)^mz^{2m}}{(2m+1)!}$}
The <sinc function> $\sin z/z$ for $z\ne0$, extended by value one at zero. The displayed <power series> has infinite <radius of convergence>, so the extension is <entire>. Its removable value follows from the first coefficient or from the sine limit. This convention differs by the argument scaling $z\mapsto\pi z$ from the normalized sinc convention.