Domains of Functions
posted by Jules .
I don't understand how to do this problem, can you please help me?
Given the functions f and g, determine the domain of f+g.
4. f(x)= 2x/(x3) g(x)=3/(x+6)

That would be the set of real numbers x that result in real values for f + g
For f(x) by itself, the domain is all numbers except 3. For g(x), the domain is all numbers except 6.
For f + g, the domain is all numbers from infinity to +infinity except 6 and 3. 
For further reading I suggest
http://www.analyzemath.com/DomainRange/DomainRange.html