## Precalculus (6th Edition) Blitzer

The function $f\left( x \right)=\frac{\sin x}{x}$ is discontinuous at the point $0$.
Consider the rational function $f\left( x \right)=\frac{\sin x}{x}$, Here, $p\left( x \right)=\sin x\text{ and }q\left( x \right)=x$ Find the zeros of the function $q\left( x \right)=x$ by $q\left( x \right)=0$, $x=0$ The zero of the function $q\left( x \right)=x$ is $0$. Thus, the function $f\left( x \right)=\frac{\sin x}{x}$ is discontinuous at the point $0$.