(a) we now the area of a rectangle is length times width, and we know the length is we also know that both the widths added together are since there are 2 sides for width we divide what they are added together by 2. .Originally Posted byLane

so now we take what we know...

and the Area is the function of

and solve for area...

now we are left with a quadratic equation that opens down, so we find the vertex...

so the area is largest when