Quadratic Root Factoring
by Barry Longden
1. Quadratic Equation
1.1. Always works
1.1.1. Benefit over other methods
1.2. Tedious calcuations
1.2.1. Drawback from other methods
1.3. Derived from the standard form of a quadratic
2. Always 2 answers
2.1. 2 distinct, real answers
2.2. 1 repeated, real answer
2.3. 2 distinct, complex (imaginary) answers
2.3.1. Always conjugates (+ or - between the real and imaginary parts)
3. Factor by Grouping
3.1. Reverse distribution
3.1.1. Find a common group (x + h) and find two groups that share this group
4. Factor by Reverse FOIL
4.1. Typical and quickest method
4.1.1. Diamond Method
4.1.2. Box Method
4.1.3. (x + h)(x + k) Method
5. Factor by Completing the Square
5.1. Another useful tool
5.1.1. Find a perfect square
5.1.1.1. Divide the b term by 2 and square it
5.1.1.2. Add this term to both sides of the equation
5.1.1.3. Solve for x