Question 830971
{{{h(x)=(x-4)/(x^3-9x)}}}
The domain is all points where the function is defined. 
This function is defined everywhere except where the denominator is zero.
{{{x^3-9x=0}}}
{{{x(x^2-9)=0}}}
Three solutions:
{{{x=0}}}
and 
{{{x^2-9=0}}}
{{{x^2=9}}}
{{{x=3}}} and {{{x=-3}}}
The domain is all points except x=-3,0,3.