Question

What is the domain and range of `y=x^2 - 5`?

Answer 1

There are no restrictions on `x` (no fractions, no roots, etc)
Range of `x:(-oo,+oo)`

Explanation:

Since `x^2>=0` (always non-negative) the lowest value that `y` can have will be `-5`. There is no upper limit.
Domain of `y: [-5,+oo)`
graph{x^2-5 [-14.24, 14.24, -7.11, 7.13]}