Quadratic Functions

 Factoring Quad. Expressions

(There is a lot here! Look for the type of problems you are having trouble with.)

https://www.khanacademy.org/math/algebra/multiplying-factoring-expression/factoring-quadratic-expressions/v/factoring-quadratic-expressions

 Quadratic Equations

http://www.khanacademy.org/math/algebra/quadtratics/v/solving-a-quadratic-by-factoring

Completing the Square

 http://www.khanacademy.org/math/algebra/quadtratics/v/completing-the-square

The Quadratic Formula

https://www.khanacademy.org/math/algebra/quadratics/solving-quadratics-using-the-quadratic-formula/v/quadratic-formula-1

 The Discriminant

https://www.khanacademy.org/math/algebra/quadratics/solving-quadratics-using-the-quadratic-formula/v/quadratic-formula-3