Finding the domain of a rational function.
f(x)=x/x^2-4

If the equation is x/(x^2-4) then I will solve it here

it's rational
therefor we can't have any impossibles like dividing by zero and square root of -1 an d stuff

f(x)=x/(x^2-4)

we know that the denomenator cannot be equal to zero so the numbers you cannot user are the numbers that will make the bottom number zero
so x^2-4=0
x^2=4
x=-2 or 2

so x cannot be -2 or 2, but it can be all other numbers so
domain=all numbers except -2 and 2

You need to show the box plots

If you make it a little more clear i can answer it