To plot the graph of a quadratic function you must first create a table of values. Then choose suitable axes that will allow all these values to be plotted. Plot the values, then draw a smooth curve through the points.

## Summary/Background

These curves are called

**quadratic curves**. When you plot them on a graph they are shaped like a hill or a valley. They always have a vertical line of symmetry going down through the middle.## Software/Applets used on this page

## Glossary

### axes

One of two straights line on a graph from which measurements are taken. One axis (the y axis) is vertical; the other (the x axis)is horizontal.

### 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.

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.

### quadratic

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

### smooth

having negligible friction

### union

The union of two sets A and B is the set containing all the elements of A and B.