240 m of fencing material is going to be used to enclose three sides of a rectangular lot. What should the

dimensions of the lot be so that the enclosed area is as large as possible? (I'm supposed to solve this using a quadratic equations but I don't know how...)

1 answer

area=lenght*width
240=length+2widdth
or length=240-2W

area=(240-2w)w
So where are the zeroes? at w=0, and w=120.

Where is the maximum? halfway between the zeroes, or at 60=width