posted by anonymous .
find the domain of composite function fog
f(x)=x/x-4; g(x)= -1/x
please show work
f(g) = g/(g-4)
= (-1/x) / (-1/x - 4)
domain is all reals except x = -1/4, 0
f(4) is not defined, but g(x) = 4 when x = -1/4.
unfortunately, g(0) is not defined, so f(g(0)) is also not defined