The Linear Function

There are many basic functions you will have to learn over the course of your math career. The first and most basic function is the linear function. A linear function is used to describe the relation of a straight line. This can be any straight line, at any angle or in any position. The general form of these functions is as follows;

y = m*x + b

Lets take a look at what all of these terms mean. It will be important to have a thorough understand of what each of them means in a mathematical and graphical sense.

First off we can establish our two variables in this equation x and y. X is the independent variable and it is denoted on the horizontal axis of a graph. Y is the dependent variable (since its value depends on the value of x) and is denoted on the vertical axis of the graph.

The letter 'm' is the slope of the line. Graphically this will give you the angle of the line. The higher the slope, the steeper the angle with the x axis. The slope can be determined from any two point on the line. You must simply sub their values into the following equation;

m = y2 - y1 / (x2 - x1)

This calculation is usually pretty easy and can be done on your calculator.

The last term, b, is the y intercept of the line. This is the point where the line crosses the y axis. If you have a graph of the line you can simply read this value directly from the graph. If you have the slope of the line, you can sub in any point on the line, rearrange, and solve algebraically for the y intercept.

So as you can see the linear function is not extremely complicated. It is a good place to start when learning about functions.

Carl Chute is an electrical engineer who has spent many years studying calculus and the linear function.