And the way you realize that is, if this was just an e to the x, then its antiderivative would just be e to the x. If you have an e to the negative four x, then you know that whatever its antiderivative is, is going to be essentially an e to the negative four x. But when you take its derivative, you're going to have to take the derivative of the negative four x part because of the chain rule. And so you're going to have to have a negative four that comes out. But we don't see a negative four over here. We don't see a negative four here, so we're obviously going to have to divide by a negative four so it cancels out. Another way to think about it is, we could have rewritten this thing.