What I want to look at now, a new sub-heading, and it's the relationship,right, between  total, average and marginal functions  As you may be aware that economists are obsessed  with the concept of the margin and there's a neat relationship a couple of relationships embedded, alright, er embedded in this relationship between total marginal and average functions that is applicable to all total marginal and average functions whether we whether we be looking at marginal cost, marginal revenue, marginal products, right, the same relationship will hold for all of them.