Finding the Domain of an Algebraic Function

  • Thread starter Thread starter NelsonsXanadu
  • Start date Start date
  • Tags Tags
    Function
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
4 replies · 2K views
NelsonsXanadu
Messages
8
Reaction score
0

Homework Statement



Find the Domain

f(x) = ___2___
x+3

Homework Equations





The Attempt at a Solution

I know this is a pretty simple question just want to make sure I'm on the right track. Wouldn't the domain be all numbers except zero? Because you can't divide by zero? How would I write this
 
Physics news on Phys.org
NelsonsXanadu said:

Homework Statement



Find the Domain

f(x) = ___2___
x+3
Another way to write this that is clearer is f(x) = 2/(x + 3)
NelsonsXanadu said:

The Attempt at a Solution

I know this is a pretty simple question just want to make sure I'm on the right track. Wouldn't the domain be all numbers except zero? Because you can't divide by zero? How would I write this
No, 0 is in the domain, because f(0) = 2/(0 + 3) = 2/3.
Yes, you cannot divide by zero. What value of x makes the denominator 0?
 
Well a -3 would make the denominator 0...
 
What you are looking for is for the *denominator* to not be zero, such that you don't divide by zero. And you're right in saying that -3 is not in the domain. Just make sure that -3 is the only thing that's not in the domain.