alrighty, domain is the numbers you can use for x without making wierd stuf happen the only numbers you can't use are the ones that cause a division by 0 or a squaer root of a negative number
no value of x will make a division by 0 but we can have a negative squaer root solve for where it will be negative and restrict that reigon
the part under the squaer root is x+6 so x+6<0 minus 6 both sides x<-6
that is where we begin to see negative squaer roots