That's what inverses do. So that's because they are inverses. This is by definition, this is what inverses do to each other. But then if you took the derivative of both sides of this, what would you get? Let me do that. So if we take the derivative of both sides of this, d dx on the left-hand side, d dx on the right-hand side, and I think you see where this is going. You're essentially going to get a version of that.