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Investigate the effect of changing $a$ and $b$.

Make sure that you are clear about these aspects of a quadratic graph:

  • its basic shape
  • its symmetry
  • the number of places where the curve crosses the x-axis
  • how the values of $a$ and $b$ affect the shape and position of the curve


A note about graphic calculators

A graphic calculator is not allowed in your exam. However you can use one for revision.

The TI-83, or similar model, can display cubic graphs for you:

  • Select the $Y=$ screen
  • Enter $Y1 = AX$x2$+BX+C$
  • Then select the GRAPH screen.
  • You can then choose different values for the constants.
  • For example, to make $A$ = $1$ press $1$ STO➧ ALPHA $A$.

Downloadable Files

If your computer is set up with either Omnigraph or Autograph then you can download these files to investigate quadratic curves further.

Autograph - quad02Autograph - quad02

Investigate quadratic curves further using Autograph.

Omnigraph - quad02Omnigraph - quad02

Investigate quadratic curves further using Omnigraph.

Software/Applets used on this page

This page uses JSXGraph

JSXGraph is a cross-browser library for interactive geometry, function plotting, charting, and data visualization in a web browser. It is implemented completely in JavaScript, does not rely on any other library. It uses SVG and VML and is fully HTML5 compliant.

This page also uses the MathJax system for displaying maths symbols.



A mathematical expression of the 3rd degree; having a x³ term but no higher one.


A rule that connects one value in one set with one and only one value in another set.


A diagram showing a relationship between two variables.
The diagram shows a vertical y axis and a horizontal x axis.


A mathematical expression of the 2nd degree; having a x² term but no higher one.

Full Glossary List