You can put this solution on YOUR website!
For the 1st equation, you can plug any value for x, since you will always get real number output. If you graph it, you get a line that extends infinitely in both directions. For the 2nd equation, look at the
term. If you plug in x=0 you get
which is not possible. So 0 is excluded from the domain of the 2nd graph. If you graphed the equation you get something like this
Notice how the curve approaches 0 but is never equal to it.