Therefore an example of a simple linear demand curve is p = $20 - (q / 10), where p is price and q is quantity. This means that for every 10 units of a product the company makes, the price it will ...

You can plot your marginal revenue curve on the same graph as your demand curve. For 11 sales, the demand curve shows a price of $4.95 – but the marginal revenue from that 11th sale is $4.45.

By using a derivative, you can take a supply function and determine the marginal revenue at any given quantity of product.