Applications of Quadratic Equations

First, for a warm-up, let’s examine a few word problems involving quadratic equations.

1.   Dimensions of a triangle from the area (8:21)  Given that the height of triangle is four units less than the length of the base, what are the dimensions of the triangle?
2.   Dimensions of a box (5:53)  Given that the volume of a box is 405 cubic units, and that the height if 9 units, the length is unknown, and the width is four more than the length, find the dimensions of the box in units.
3.   Projectile motion (5:52) A ball is shot into the air from a building that is 50 feet tall at an initial velocity of 20 feet per second.  How long will it take to hit the ground?Note: this video does not discuss the equation , and probably should.

And here is a proper application of quadratic functions to mosquito populations.

1.   Modeling mosquitos with quadratics (8:39)
2. Practice using quadratic models

If you’ve always had a secret dream of finding lots of money, here is a question for you: So, do you buy the rope or not?