Calculate total cost, disregarding any fixed costs.
Total profit from marginal profit. Poyse Inc. has a marginal-profit function given by
$$
P^{\prime}(x)=-2 x+80
$$
where $P^{\prime}(x)$ is in dollars per unit. This means that the rate of change of total profit with respect to the number of units produced, $x,$ is $P^{\prime}(x)$. Find the total profit from the production and sale of the first 40 units.