# How do you solve #y = -sqrt(x+4)# and is it a function?

##### 2 Answers

Yes

#### Explanation:

Given the formula:

#y = -sqrt(x+4)#

Note that for any

If

So the (implicit) domain of this relation is

Another way of expressing the "unique value of

graph{-sqrt(x+4) [-10, 10, -5, 5]}

This **is** a function

#### Explanation:

There is no **solving** involved;

is a function because for all valid values of

this relation generates one and only one value for

You might compare this to

**not** a function since two values can be generated from a single value of