Answer
The function $ f\left( x \right)=c $ is not discontinuous for any number.
Work Step by Step
Consider the rational function $ f\left( x \right)=c $,
Here, $ p\left( x \right)=c\text{ and }q\left( x \right)=1$
$ p\left( x \right)=c $ is a constant function and a constant function is continuous for every number x.
Now, find the zeros of the function $ q\left( x \right)=1$ by substituting $ q\left( x \right)=0$,
That is, $1=0$
As $1\ne 0$ so, there is no zero of the function $ q\left( x \right)=1$.
Thus, the function $ f\left( x \right)=c $ is not discontinuous for any number.
