Answer
The function $ f\left( x \right)=\frac{1-\cos x}{x}$ is discontinuous at the point $0$.
Work Step by Step
Consider the rational function $ f\left( x \right)=\frac{1-\cos x}{x}$,
Here, $ p\left( x \right)=1-\cos 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{1-\cos x}{x}$ is discontinuous at the point $0$.
