A manufacturer of tennis rackets finds that the total cost C(x) (in dollars) of manufacturing x rackets/day is given by

C(x) = 300 + 2x + 0.0002x²

Each racket can be sold at a price of p dollars, where p is related to x by the demand equation

p = 11 0.0003x

If all rackets that are manufactured can be sold, find the daily level of production that will yield a maximum profit for the manufacturer. Hint: The revenue is R(x) = px, and the profit is P(x) = R(x) C(x).