1. Using the x-intercepts to Rewrite a Quadratic in Graphing Form

2. Graphing Form for a Parabola y = a(x – h) 2 + k ( h, k ): The Vertex The value of a opposite same Positive: Opens UpIf it Increases: Vertical Stretch Negative: Opens DownIf it Decreases: Vertical Compression

3. Different Forms For a Quadratic Parent Graph: y = x 2 Factored Form: y = __( __x ± __ )( __x ± __) Standard form: y = ax 2 + bx + c Graphing Form: y = a(x – h) 2 + k Same “a”

4. Justification that the “a” in Standard and Graphing Form are the same Same a!

5. Standard Form to Graphing Form: Factoring Use an algebraic method to write in graphing form. 2 1. Find the value of a: 2. Find the x-intercepts 3. Average the x-intercepts for h 4. Substitute h into the rule for k 5. Substitute a, h, k into the graphing form WARNING:This method does not work if there are no x-intercepts

6. Instead of Factoring, use the Quadratic Formula

7. Standard Form to Graphing Form: Quadratic Formula Use an algebraic method to write in graphing form. 2 1. Find the value of a: 2. Find the x-intercepts WARNING:This method does not work if there are no x-intercepts 3. Average the x-intercepts for h 4. Substitute h into the rule for k 5. Substitute a, h, k into the graphing form