# Math Help - domain of a function

1. ## domain of a function

Hi,

I can not figure out the answer to the following problem, can someone please explain?

f(x)= X+4/X-3

What is it's domain?

Thanks!

2. Originally Posted by dasani
Hi,

I can not figure out the answer to the following problem, can someone please explain?

f(x)= X+4/X-3

What is it's domain?

Thanks!
You can think of the domain of a function as all x-values for which the function is defined. here we see there is a problem at x = 3. if x = 3, the denominator becomes zero and the function undefined. thus the domain of this function is given by:

dom(f) = all real x where x not=3

or

dom(f) = {all x| x not=3}

or

dom(f): (-infinity,3)U(3,infinity)