A profit is earned when revenue exceeds cost. Suppose the profit function for a skateboard manufacturer is given by P(x) =30x − 0.3x 2 − 250, where x is the number of skateboards sold. a. Find the...

A profit is earned when revenue exceeds cost. Suppose the profit function for a skateboard manufacturer is given by P(x) =30x − 0.3x² − 250, where x is the number of skateboards sold.

a. Find the exact profit from the sale of the thirtieth skateboard.

b. Find the marginal profit function and use it to estimate the profit from the sale of the thirtieth skateboard.