Functions

The examples and notes below will help you to complete the tables for drawing graphs of quadratic functions.

Click here for an animation that will complete the table, draw a graph and help you to answer questions about the graph. 

A graph can also be used to solve quadratic equations.

Graphing Lines

2x + 3y = 4 and 3x = 4y are typical examples of linear equations. The solutions for these come in pairs - for every possible value of x there is one value of y that will work and vice versa. If the solutions of these equations are plotted is it found that all the points lie on a straight line.

The pencast below shows the method for finding the points where the line crosses the X-axis and the Y-axis. This method is useful when you want to draw a graph of the line.

You can use this method to solve simultaneous equations, just put both lines on the same graph.

Graph of a Line
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