Question

What is the domain of `f(x)=sqrt(4-x^2)`?

Answer 1

`-2 <= x <= 2`

Explanation:

We are dealing with a square root here. Since squares are non-negative, we can only obtain a valid value from the square root if it involves non-negative values

`4 - x^2 >= 0`

`=> 4 >= x^2`

`=> x^2 <= 4`

`=> -2 <= x <= 2`