Question

How do you find the domain in interval notation for `f(x)=(x+4)/(x^2-4)`?

Answer 1

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

`f(x)=(x+4)/color(red)[(x)^2-(2)^2]`

`f(x)=(x+4)/color(red)[(x+2)(x-2)]` `lArr (a)^2-(b)^2=(a+b)(a-b)`

`x` can not be `-2` or `2`, otherwise `f(x)=oo`

Domain:
`x in RR` except `-2` and `2`.