The domain of a function is composed of all real numbers for which the function is defined. In the case of a rational expression, such as the given one the function is undefined when its denominator is zero.
Now, solving
[tex]x^{2}-16=0[/tex]for x we get:
[tex]\begin{gathered} x^2-16=x^2-4^2=(x-4)(x+4) \\ \text{Therefore, x=4 or x=-4} \end{gathered}[/tex]Then, the domain of the function is al real numbers except for 4 and -4.
