Theory:

Reciprocal Function:
A function \(f: \mathbb{R}-{0} \rightarrow \mathbb{R}\) defined by \(f(x) = \frac{1}{x}\) is called a reciprocal function.
The graphical representation of a reciprocal function is given by:
 
Reciprocal function.png
Constant Function:
A function \(f: \mathbb{R} \rightarrow \mathbb{R}\) defined by \(f(x) = c\), for all \(x \in \mathbb{R}\) is called a constant function.
The graphical representation of a constant function is given by:
 
COnstant function.png