Equation Grapher

Introduction

How To Plot A Function

How To Analyze Functions

How To Calculate The Value Of An Integral

How To Paste A Graph Into A Word Document

For More Information


Introduction

Equation Grapher is a function plotting/analyzing program. It allows you to draw graphs like y=2x and y=sin(x+10)-cos(x). It is possible to have up to 13 graphs plotted at the same time.

Once you have plotted a function, Equation Grapher automatically finds roots, maximum/minimum, intersections etc.

It can also calculate and view integration area.

You can change the range of the graph, either by using the built in zoom functions, or by manually typing in the range values.

If you like, you can copy the graph window and paste it into your word processor. Of course, it is possible to save your work and continue at another time.


How To Plot A Function

To plot a function, place the cursor in the combo box and type in the expression like this:

Then press Enter, and the function is plotted in the Graph window.

If you want to plot another graph in the same window, just repeat the procedure. It is possible to have up to 13 graphs plotted at the same time.

To clear the Graph window, select File|New.

Besides the four rules of arithmetic (+, -, * and /), the following operators and functions can be entered in the function expression:

When you have become familiar with Equation Grapher, you would probably type the names of these functions on the keyboard rather than selecting them from the menu.

A small explanation: Sqrt means Square Root. Unfortunately, the square root character does not exist in the ANSI character table.


How To Analyze Functions

Once you have plotted a function, Equation Grapher automatically finds roots, maximum/minimum, intersections etc.

The following can be found in the Solve menu:

·	Root

·	Maximum

·	Minimum

·	Y-Intersection

·	Intersection

·	Y-Calc

·	X-Calc

For example, to find the minimum value of y=x^2-x-2, plot the function and select Solve|Min. Equation Grapher now asks you to select a range on the graph with the mouse. To do this, move the mouse pointer over the Graph window. When the pointer is at the upper left of the minimum point, press the left mouse button and keep it down while you move the mouse pointer to the lower right.

When you release the mouse button, Equation Grapher will search for a minimum point within the selected area. If there is one, it will be marked with a red circle, and its coordinates will be printed on the status bar.


For More Information

If you have any suggestions of what you would like to see in future versions, or questions concerning how to use Equation Grapher or how to order it, please e-mail friberg@chapman.karlskrona.se

or write to:

Equation Grapher

Markus Friberg DATA

Klimatgatan 7

371 51 Karlskrona

SWEDEN

For the latest information on Equation Grapher, have a look at http://www.algonet.se/˜marfri


How To Calculate The Value Of An Integral

Equation Grapher can calculate the value of an integral. To do this, first switch over to Integral Mode.

Then, type in the function that is to be integrated, along with the integration limits separated by semicolons. For example, let us say that we want to calculate the value of the following:

Then, type x^2-x ;2 ;3 like this:

As you can see, the integral area is filled with blue, and the value of the integral is printed on the status bar.


How To Paste A Graph Into A Word Document

With Equation Grapher, it is very easy to copy a graph and paste it into your word processor or paint program. Just follow these steps:

1. 	Start Equation Grapher and plot a function.

2. 	Choose Graph|Copy from the menu.

3. Start your word processor or paint program, and select Edit|Paste in the menu. (This will look different in other languages. For example, in Swedish it is Redigera|Klistra in.)

Hint: If you have pasted the graph and want to resize it, do not do this in the word processor or paint program. Instead, switch back to Equation Grapher, change the size of the Graph window and repeat the procedure above from point 2 and on. By doing this, all the information in the picture will remain, which yields a good result when printing.