This video will cover a quadratic application involving finding maximum area of a region with given restrictions of material. This example problem gives one way the problem could be set up.
Source: Created by Crystal Kirch using Camtasia for Mac
This video goes over another way that a maximum area problem could be set up. Pay close attention to the wording of the problem and TRY IT ON YOUR OWN FIRST!
Source: Created by Crystal Kirch using Camtasia for Mac