A rectangular paddock already fenced on one side, with 300m of fencing, whats the maximum area of the enclosur

A rectangular paddock already fenced on one side, with 300m of fencing, whats the maximum area of the enclosure?|||Let x be the width and y be the length of the fence.


Perimeter=2x+2y=300


2y=300-2x


y=150-x


Area = xy


A=x(150-x)


A=150x-x^2


dA/dx = 150-2x =0


2x=150


x=75


2(75)+2y=300


150+2y=300


y=75


d^2A/dx^2=-2 %26lt; 0, so the area is maximum at length = 75m and width=75m.