Question

What is the domain of the function 9x/x^2-4

Answer 1

Domain: The set of all possible input values (commonly the "x" variable) It is the set of all real numbers for which a function is mathematically defined.  

$\mathrm{The\:function\:domain} \ x\ \textless \ 0 \ or \ x\ \textgreater \ 0$ 

The function has noun defined points nor domain constraints. Therefore, 
the domain is x=0