Question 369593
The domain of the function is all the x values for which {{{f(x)}}} is defined.
The square root function is defined as long as the argument is not negative.
{{{x-9>=0}}}
{{{x>=9}}}
Division by zero is also undefined so the x value when the denominator equals zero is not in the domain. 
{{{x-9=0}}}
{{{x=9}}}
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So both of those must hold: x must be greater than or equal to 9 and x cannot equal 9, so that leaves that {{{x>9}}}
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Domain:{{{x>9}}} or in interval notation, ({{{9}}},{{{infinity}}})
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{{{graph(300,300,-2,18,-10,10,0,4/sqrt(x-9))}}}