First, we need to find the composite function of f ∘ g.
We need to write the function f(x) in terms of g(x).
Then:
[tex]\begin{gathered} (fog)(x)=\frac{6}{g(x)+7}=\frac{6}{x+5+7} \\ =\frac{6}{x+12} \end{gathered}[/tex]
Now, to find the domain we need to look at the x values that the function can take.
The function is a rational function, then the domain is given using the denominator because it can be equal to zero.
x+12 = 0
x=-12
Therefore, the domain is the interval (-∞.-12)U(-12,∞)
