Your Welcome Shannon

domain of  f(x) = x^2  is all real numbers

TEST:
f(1) = 1^2 = 2 [Works]
f(22) = 22^2 = 484 [Works]
f(0) = 0^2 = 0 [Works]

These are all defined points
|
|
|
|
domain of  f(x) = 2/x  is all real numbers except 0

Test:
f(1) = 2/1 = 2 [Works]
f(98) = 2/98 = 1/49 [Works]
f(0) = 2/0 = Undefined [Doesn't Work, why?]

It should be known that you can not divide by 0, not allowed thus it is undefined.
|
|
|
|
To find the domain of a function start with solving for x in the denominator(bottom) of a fraction.
So we have:
	f(x) = (2x) / (x^2 - 4)
Focus on the denominator first:
	x^2 - 4
Now solve for x by first factoring:
	=(x^2 - 4)
	=[(x-2)(x+2)]
Solve for x further by getting x by itself:
	(x-2)  (x+2)
	x=2    x=-2