AlgebraLAB
 
 
Site Navigation
Site Directions
Search AlgebraLAB
Activities
Career Profiles
Glossary
Lessons
Reading Comprehension Passages
Practice Exercises
StudyAids: Recipes
Word Problems
Project History
Developers
Project Team






Algebra I Recipe: Graphing a Quadratic Equation
A. Definitions
  1. Parabola – the graph of a quadratic function, which is u-shaped
  2. Vertex Point – it’s the highest or lowest point on the graph
  3. Axis of Symmetry – the vertical line that goes through the vertex point
  4. Standard Form - y = ax² + bx + c
B. Steps for Graphing a Quadratic Equation in Standard Form
  1. Determine if the graph will open up or down.
    • Opens up if "a" is positive.
      The vertex point will be the minimum point.
    • Opens down if "a" is negative.
      The vertex point is the maximum point.
  2. Find the vertex point.
    • Find the x-value by x = - b/(2a).
    • Find the y-value by substituting the x-value into the equation and solving for "y".
  3. Find more points to determine the graph.
    • Choose two integers larger than the x-value of the vertex point.
    • Choose two integers smaller than the x-value of the vertex point.
    • Substitute these values in place of "x" in the equation and solve for "y".
    • Four ordered pairs have been found
  4. Graph and connect all points that have been found.
ExamplesExamples:
y = 2x² - 8x + 6

y = -2x² + 8x – 5




G Redden

Show Related AlgebraLab Documents


  Return to STEM Sites AlgebraLAB
Project Manager
   Catharine H. Colwell
Application Programmers
   Jeremy R. Blawn
   Mark Acton
Copyright © 2003-2017
All rights reserved.