How do you find the domain of f(x)= (4x)/ sqrt(x-4)?

1 Answer
Nov 6, 2015

Domain = (4, oo)

Explanation:

When looking for domain, it is the x values that exist from negative infinity to positive infinity. For this equation, if you plug in any number where x<=4, we got either a negative number or sqrt(0), both of which do not exist. However any value x > 4, the denominator gives us a real value. Because of this, x exists from 4 to oo. You use a parenthesis next to 4 and not a bracket because 4 is not included in the domain.