Sinc Function

Definition

For $x\ne 0$, the sinc function is defined as

$$\mathrm{sinc}(x)=\frac{\sin (x)}{x}$$

and for $x=0$,

$$\mathrm{sinc}(0)=\underset{x\to 0}{\lim }\frac{\sin (x)}{x}=1$$