Answer
-7 and 7
Work Step by Step
In order to determine the domain restrictions, we must set the denominator equal to 0. You must always do this, regardless of what the numerator is (even if one of the factors cancels):
$x^2 - 49 = 0$
Factor the left-hand side as a difference of squares:
$(x + 7)(x - 7) = 0$
Then, we know that either $x + 7 = 0$ or $x - 7 = 0$. Therefore, we know that our domain restrictions are both -7 and 7.
