Question 176999
The domain is all of the x values that make f(x) defined. 
There are two restrictions on the domain to be concerned about. 
First, the square root can only have zero or positive values as arguments, because the square root of a negative number is undefined. 
{{{x-4<0}}}
{{{x<4}}}
Second, since it's a fraction, the denominator cannot be zero because division by zero is undefined. 
Find the point(s) where the denominator equals zero.
{{{x-4=0}}}
{{{x=4}}}
If we put the two together, x cannot be less than 4 and x cannot be equal to 4. 
Therefore the domain is x such that x is greater than 4.
Domain:({{{4}}},{{{infinity}}})
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To get the range look at the domain. 
Near x gets close to 4 (say 4.001), the denominator gets very small, the value of f(x) gets zero large.
As x gets very larger, the denominator gets very large, the value of f(x) goes towards 0.
Range:({{{0}}},{{{infinity}}})