Question

A farmer has 2,400 feet of fencing and wants to fence off a rectangular field that borders a straight river. He needs no fence along the river. Write the function that will produce the largest area if x is the short side of the rectangle.

f(x) = 2400x − x2

f(x) = x2 − 2400

f(x) = 2x2 − 2400

f(x) = 2400x − 2x2

Answer 1

I chose D

Answer 2

\[\Large 2x+y=2400\]
\[\Large y=2400-2x\]
\[\Large A=xy\]
\[\Large A=x(2400-2x)=~~2400x-2x^2\]

Answer 3

Is that correct

Answer 4

@tkhunny

Answer 5

Is there a drawing? Without some indication, we don't know which is the short side. I'd work it both ways and see how it goes.

Answer 6

There's no drawing but that's what I presume to be the shortest side