How do you find the domain of f(x) = - sqrt(2 / (x^2 - 16))?

1 Answer
May 18, 2015

You have to check:

  • the denominator must be different from zero
  • the expression under the square root must be positive

So we must have x^2 - 16 != 0 => x != +-4

And (the numerator doesn't interfere):

x^2 - 16>=0 => x>=4 or x<=-4

So, intersecting, we have:
D := {x in RR : x>4 or x<-4}