Question: ENERGY EXPENDED BY A FISH It has been conjectured that a fish swimming a distance of L ft at a speed of √ ft/sec relative to the water and against a current flowing at the rate of u ft/sec (u
E(v) = aLv3/(v - u)
Where E is measured in foot-pounds (ft-lb) and a is a constant. Find the speed √ at which the fish must swim in order to minimize the total energy expended. (Note: This result has been verified by biologists.)