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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

## Summary/Background

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 = (X-A)(X-B)Then select the GRAPH screen. You can then choose different values for the constants A and B. For example, to make A = 1, press 1 ALPHA A.

Investigate quadratic curves further using Autograph.
Investigate quadratic curves further using Omnigraph.

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, and uses SVG and VML. JSXGraph is easy to embed and has a small footprint: less than 100 KByte if embedded in a web page. No plug-ins are required! Special care has been taken to optimize the performance.

## Glossary

### cubic

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

### function

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

### graph

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

### plot

To mark a point on a graph accurately by using its coordinates.