x copies of an edition is given by C(x) 80+ 0.10x +0.001x2 dollars. R(x) also the marginal revenue and profit, if you have produced and sold 500 copies of the latest edition. revenue so the profit is at a x copies of an edition is given by C(x) 80+ 0.10x +0.001x2 dollars. R(x) also the marginal revenue and profit, if you have produced and sold 500 copies of the latest edition. revenue so the profit is at a