brody's farm borders a river. He buys 1,000 meters of fencing. What dimensions maximize the area of the farm?

Question

anonymous · Answer

First write what you need to find
 A = LW
 Then what you know (since it is against a river you only need three sides hence the one W)
 P = 2L + W
 1000 = 2L + W
 Solve for one variable (I chose W)
 W = 1000 - 2L
 Plug into Area equation
 A = 1000L - 2L^2
 Take the derivative
 dA/dL = 1000 - 4L
 Solve for L 
 L=250
 Plug into perimeter equation
 1000 = 2(250) + W
 W = 500
 Therefore the dimensions should be 250 m x 500 m given that it is against the river.

anonymous · Answer

you got this answer from yahoo

anonymous · Answer

no I figure it out by myself did I get it right or not