Find the Domain g(x)=1/x-3/x+9

Question

How do you find the domain of this problem? I'm having a hard time understanding 

Answer 1

I am assuming that the function is:  g(x) = 1/x - 3/(x+9)

 

Domain = {x l x ≠ 0 and x + 9 ≠ 0}

 

           = {x l x ≠ 0, -9}  = (-∞, -9) ∪ (-9, 0) ∪ (0, ∞)

Answer 2

The domain is the set of x values in which g(x) exists, or is defined.  Since the denominator part of the function cannot be zero, we set the denominator equal to zero and solve for x. 

 

So your domain is all real numbers for x, EXCEPT the values of x that you solved for.