ANSWER
[tex](-\text{ }\infty,\text{ +}\infty)[/tex]EXPLANATION
We have to first find (f o g) and (g o f).
(f o g) means f(g(x)), that is:
[tex]\begin{gathered} f(g(x))\text{ = 6(}\frac{x\text{ + 8}}{6})\text{ - 8} \\ (f\text{ o g)(x) = x + 8 - 8} \\ (f\text{ o g) = x} \end{gathered}[/tex](g o f) means g(f(x)), that is:
[tex]\begin{gathered} g(f(x))\text{ = }\frac{6x\text{ - 8 + 8}}{6}\text{ = }\frac{6x}{6} \\ (g\text{ o f) = x} \end{gathered}[/tex]The two functions (since they are identical) do not have any undefined points.
The domain of a function is the set of all the possible values of x.
Therefore, since there are no undefined points in the function, the domain is (-infinity, + infinity)
