In this section you will learn about complex numbers, the quadratic equation, what the discriminiant is, the parts of a parabola, and the how to know which way the parabola will open.  You will also learn how to make quadratic models.  You learn about imaginary numbers (ugh!).  Only mathematicians would ever think of numbers that really don't exist, yet do exist.  Anyway, you will learn how to factor quadratic equations, how to use a method called "completing the square", how to know which equation to choose, how not to lose or gain a root, and more about the discriminant.  The best thing about this section is learning how to make a quadratic model.  Now why would you want to do this?  It has many uses.  For example, it will tell you how far away a ball will land if you hit it 1 meter above the ground and its path peaked at 60 meters. You can also find out if a trailer will be able to go under a bridge BEFORE it is too late.  As you can see, learning your quadratic functions can be very helpful.