math
posted by aa on .
what is the largest are of rectangular area that can be enclosed in sixteen meter fence
?

I am sure that I have answered this one recently
Let the width of the rectangle = w and the height = h
2w+2h=16 or
w=8h
the area=wh or
area = (8h)h = 8hh^2 =a
there are a couple of ways to finding the maximum area. You could plot area against h and find where h is a maximum.
Alternatively the area is a maximum when da/dh=0
da/dh=82h, which is zero when h=4
i.e. the maximum area is when h=4 and w=4
so the largest area is 16 m^2