You can
put this solution on YOUR website!You're on the right track. I'll start where you left off.

Start with the given equation

or

Take the square root of both sides. (note: don't forget the plus/minus)
Now since you CANNOT take the square root of a negative number, this means that "x" is not a real number. So this means that you can plug in ANY number in for "x" and no division of zero will occur.
So the domain is all real numbers (ie there are no restricted values)