Let's say this is orange juice. If I know that next gallon is going to cost me $5 to produce, and I can sell it for $6, then I'm gonna do it. But if that next gallon, if I'm up here, I've already produced a lot, and I'm taking all the oranges off the market, and now I have to transport oranges from the other side of the planet or whatever it might be, and now that incremental gallon of oranges or a gallon of orange juice costs me $10 to produce, and I'm not going to be able to sell it for more than $6, it doesn't make sense for me to produce it anymore. So in a calculus context, or I guess you say in an economics context, if you can model your cost as a function of quantity, the derivative of that is the marginal cost. It's the rate at which costs are increasing for that incremental unit. And there's other similar ideas. If we modeled our profit as a function of quantity, if we took the derivative, that would be our marginal profit.