precalculus 12 grade

Question

Ryan has 3000 ft of fencing to enclose a rectangular field for his horses. One side of the field lies along a river, so only 3 sides require fencing. Express the area of the field as a function of length (y) of the field

A(y)=

Answer 1

A(y) = 1500y - (y^2)/2

2x +y = 3000

A = XY = x(3000-2x) = A(x)

A = XY = y(3000-y)/2 = 1500y - (y^2)/2 = A(y)

Answer 2

A(y) = y((3000 - y) / 2)