Question: Application exercise. Suppose that the total revenue R that a seller receives from the sale of two goods, x and y, along with the advertisement expenditure, ν, is given by the function R = f (x,y,v) = x0.4y0.4v0.2. Also suppose that x = g(v) = 0.5v and y = h(v) = v. Find the change in the total revenue when advertisement expenditure changes by an infinitesimally small amount.