Question

How do you find the domain of `sqrt(x+4)`?

Answer 1

The domain is `x >= 4`

Explanation:

Since square roots are only defined when the expression under the square root is non-negative, to find the domain we set the expression under the square root greater than or equal to zero:

`x - 4 >= 0`
`x >= 4`

Answer 2

`[-4,oo)`

Explanation:

Firstly you know that there can't be a negative under a square root `sqrt(-1)` any negative leads to the function being undefined

So when `x+4<0` i.e. it is lower than zero you know there is no domain

So when `x+4>=0` the domain exists so it eixsts when `x>=-4`

So the domain is `[-4,oo)`