9514 1404 393
Answer:
- 160 ft (out from the river)
- 320 ft (parallel to the river)
Step-by-step explanation:
Let x represent the length of fence parallel to the river. Then the dimension of perpendicular to the river will be half the remaining fence: (640-x)/2. The total area will be ...
A = x(640-x)/2
This is the equation of a parabola that opens downward. It has zeros at x=0 and x=640, so its axis of symmetry is x = (0+640)/2 = 320. That is, the peak of the area curve is found when x=320.
The dimensions of the garden with the largest area are 160 ft wide by 320 ft long, where the long side is the river side.
