A rectangular plot of farmland will be bounded on one side by a river and on the other three sides by a single-strand electric fence. With 400 m. of wire at your disposal what is the largest area that you can enclose, and what are its dimensions? Use the convention that length is longer than the width.

Question

anonymous · Answer

2x+y=400 
A=xy area of farmland
y=400-2x
A=400x-2x^2
A'(x)= 400 -4x derivative of area with respect to x
0=400-4x find out where f ' equals 0
4x=400
x=100
A'(x)= 400 -4x
A''(x)= -4 check 2nd derivative. if negative then relative max at x=100
2x+y=400
y=200

dimensions 100x200
hope it helped

anonymous · Answer

YES IT DID ty