And even f of four is actually defined, but we're getting closer and closer to it. And we see once again we are approaching five. Even if f of four was not defined, on either side we would be approaching negative five. So this is also approaching negative five. And since the limit from the left-hand side is equal to the limit from the right-hand side, we can say, so these two things are equal. And because these two things are equal, we know that the limit of f of x as x approaches four is equal to five. Let's look at a few more examples.