Step-by-step explanation:
For a rational function, we cannot values in the domain that will make the denominator 0.
So set the denominator =0
[tex] {x}^{2} - 1 = 0[/tex]
[tex] {x}^{2} = 1[/tex]
[tex]x = 1[/tex]
or
[tex]x = - 1[/tex]
So the answer is (-1,1)
