Question

How do you find the domain of `g(x) = sqrt(x^2 - 9)`?

Answer 1

Domain in interval notation (-infy, -3]U [3. inf) or,
All real numbers x: x`<=`-3 or x`>=`3.

Domain would be all real numbers x such that `x^2-9` is `>=`0. On solving this inequality, it would be `x^2` `>=`9,
x `>=3`, or -x`>=`3 or x `<=`-3