Question

What is the domain of `f(x)=(x^2+2x)/(x^2-4)`?

Answer 1

The function `f(x) = (x^2 + 2x)/(x^2 - 4)`
is defined for all real values except those which cause
`x^2 - 4` to be `= 0`

That is, the domain of `f(x)`
is the set of all real numbers excluding (+2) and (-2)
graph{(x^2 +2 )/(x^2 - 4) [-6.24, 6.25, -3.12, 3.12]}