A national food service runs food concessions for sporting events throughout the country. The company's marketing research department chose a particular football stadium to test market a new jumbo hot dog. It was found that the demand for the new hot dog is given approximately by
p = 8 - 2 In x 5 ≤ x ≤ 50
where x is the number of hot dogs (in thousands) that can be sold during one game at a price of $p.
(A) Find the local extrema for the revenue function.
(B) On which intervals is the graph of the revenue function concave upward? Concave downward?