And so one way to think about it here is as we try to figure out what this expression equals as we get closer and closer to three, we're trying to approximate the limit from the left. So limit from the left. And why do I say the left? Well, if you think about this on a coordinate plane, these are the x values that are to the left of three but we're getting closer and closer and closer. We're moving to the right but these are the x values that are on the left side of three, they're less than three. But we also, in order for the limit to exist, we have to be approaching the same thing from both sides, from both the left and the right. So we could also try to approximate the limit from the right.