A bird is released at point A on an island, 5 miles from the nearest point B on a straight shore. The bird flies to a point C on the bank and then flies along the bank to its nesting area D (see figure). Suppose the area requires 10 Kcal / mile of energy to fly over land and 14 Kcal / mile to fly over water. a) Find a function that models the energy expenditure of the bird
b) If the bird instinctively chooses a path that minimizes its energy expenditure, how far does it fly?