MathDB

2

Part of 1967 Vietnam National Olympiad

Problems(1)

VietNam MO 1966-Pr.2

Source:

2/18/2007
A river flows at speed u. A boat has speed v relative to the water. If its velocity is at an angle α\alpha relative the direction of the river, what is its speed relative to the river bank? What α\alpha minimises the time taken to cross the river?
trigonometry