Find the domain of the composite function fog 1 The domain c

Find the domain of the composite function fog. 1 The domain contains all real numbers except for which two values? (smaller value) (larger value)

Solution

g(x)=-8/x

domain of g does not contain 0

fog

=f(g(x))

=1/((-8/x)+9)

=1/((-8+9x)/x)

=x/(9x -8)

function is undefined if 9x -8=0

=>x =8/9

so domain is all real numbers except 0, 8/9