A rectangular field is fenced on three sides with total fence length L, the fourth side along a river. Maximum area is:
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A rectangular field is fenced on three sides with total fence length L, the fourth side along a river. Maximum area is:

G1 Physics · Accepted Answer

Let width=x and length=L−2x. A=x(L−2x). A'=L−4x=0 → x=L/4. Then Aₘₐₓ=L²/8.