Subject: Domain and Range What is the domain of: f(x) = 1/(x + 4) I have looked at this question and I think that the domain would be that x cannot = 4, XER. Am I even close to the right answer?
Hi Stacey, To find the domain of a function you need to ask yourself the question "what xvalues am I allowed to use". It's often easier to look at a function and ask yourself "what xvalues am I NOT allowed to use". In this case, since division is involved, you know you cannot divide by zero. What xvalue would lead to a division of zero? In this case x=4. Hence the domain is any real number, EXCEPT x=4.Similarily, the domain of f(x) = x / (x+1)(x2) would be any xvalue except x=1 and x=2. If you have a function with an even root in it, remember that you cannot take an even root of a negative number. As a result, in a function such as f(x) = sqrt(x1) only xvalues greater than x=1 are allowed, hence the domain is all x>1. Hope this helps,Patrick
