Purple Math
Purplemath: Completing the Square: Deriving the Quadratic Formula
View examples on completing the square and deriving the quadratic formula. The key to solving by completing the square is "practice, practice, practice". By so doing, the process will become more "automatic", and you'll be much more...
Cool Math
Coolmath: Solving Quadratics Recap
This CoolMath resource reviews the ways to solve quadratic equations: factoring, finding square roots, and using the quadratic formula.