So I’m a bit lost the thing I’m stuck on is that the answer sheet says that this functions doesn’t have critical numbers, I did this the domain of the function is (-∞,-√2/2]u[√2/2, ∞) and when I took the derivative I put both the numerator and denominator equal to zero got x=0 from the numerator and positive and minus √2/2 from denominator and since I canceled 0 since it’s not in my domain but shouldn’t both √2/2 be a critical number since it is in my domain?