Graphs of Functions

After studying this section, you will be able to:

recognise and use the form of the equation for a straight line (linear function)
draw and recall the graphs of simple non-linear functions

Equations of straight lines

Graphs of non-linear functions

Sometimes you will be able to see a pattern in the results table. If it breaks down for a point, you may have made a mistake.

First, fill a table of values by substituting into the equation − you may well be asked to fill in a partially complete one.

Then draw as smooth a curve as possible through the points − if the smoothness is interrupted by a point, you have probably made a mistake − check your substitution. All the graphs you will be asked to draw will be smooth curves − don’t join the points by a series of short straight lines; you will not get any marks.

You need to be able to recognise and draw graphs like these:

NOTE:

In the exam you will probably be given a 2 mm grid, possibly with the axes labelled.

Always check the values of the units on the x and y-axis scales.

PROGRESS TEST

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