So L'Hopital's rule, it applies to this last step. If this was the problem we were given, we said, hey, when we tried to apply the limit, we get the limit as the numerator approaches 0 is 0. Limit as this denominator approaches 0 is 0. The limit as the derivative of the numerator over the derivative of the denominator, that exists and it equals 6. So this limit must be equal to 6. Well, if this limit is equal to 6, by the same argument, this limit is also going to be equal to 6. And by the same argument, this limit has got to also be equal to 6.