Question 136623
Remember f and g are functions, f(x) and g(x) are the values of those functions at x.


{{{f(x)=x+6}}}, {{{g(x)=4/(x+8)}}}


(f°g)(x) = {{{f(g(x))=g(x)+6=(4/(x+8))+6}}}


(f°g)(x) = {{{(4+6(x+8))/(x+8)=(6x+52)/(x+8)}}}


So, for what values of x is (f°g) undefined?  The domain is the rest of the real numbers.