Help with econ homework!!

our total utitily curve is just at the peak, so if you eat more, your total utitily decrease.

When marginal utility is zero, the marginal utility curve is at its peak. Any additional consumption will make the extra utility to be negative, making the marginal utility curve to start sloping down. Marginal utility (mu)is the extra satisfaction derived from consuming an additional unit of a product or service. Initially, mu keeps increasing as more of an item is consumed. After a certain point, mu will still be positive, but reducing until it gets to a level of zero, and then negative eventually. That explains why discounts are offered to induce large purchases, because consumers attach progressively lower values to subsequent units consumed.