Question

How do you find the domain in interval notation for `f(x)=(x+6)/(x^2+5)`?

Answer 1

The domain of a function is all the values that `x` can take (in order to avoid having something like `a/0`, which isn't defined).

In your case, `x^2+5 > 0` with `x in RR`; therefore, there is no way you could have a division by zero.

Thus, the domain `D = RR` or, in interval notation, `D = ]-oo;+oo[`.