Before you can apply L'Hopital's rule, you have to check whether it applies. Under what conditions can you use it? Can you, here?
Also, please state the instructions given for this problem. I recently helped a student in person who had not noticed that it said to use L'Hopital's rule if it applied and was useful. That led to a good discussion of what those two words meant! Not all the problems needed, or benefited from, the rule, and it wasn't always applicable at all.
As an aside, you might write the problem as "lim{x->0} 1/x^2", if you don't want to try the more complicated formats.