__The Quadratic Equation
Calculator__

__Created
By____
David@TechForText.com,
©2010__

__To contact the author use the
above email address, or__

__Left click on these words for a website
communication form.__

__This website
provides a free calculation device (____The Quadratic Equation
Calculator____) in the online
JavaScript and spreadsheet formats, for solving quadratic equations. The
online version is embedded in this webpage, a few lines below this
paragraph. If you want the spreadsheet version, (available in Microsoft
Excel, and OpenOffice Calc) or additional information, scroll all the way down,
beneath the online Calculator. __Alternatively, you
can use the hyperlink table of contents of this website, which is located just
below the online calculator. **To go directly to the
table of contents left click on these words.**

** **

__The
Online Version of The Quadratic Equation Calculator__

__THE HYPERLINK TABLE OF CONTENTS OF
THIS WEBSITE__

__Left
click with the mouse, on the UPPER PORTION of the blue words that relate to the
topic or subtopic you are interested in.__

**If you want a diverse assortment of
calculation devices for algebra and trigonometry, go to the main website at
www.TechForText.com/Algebra****,
****which can be done by left clicking on
these words. **

**The Online
Version of The Quadratic Equation Calculator**
2

**System
Requirements for the Downloads,**
12

**And Links
to Obtain the Free Downloads**
12

**The
Software You Need for the Downloads**
12

**Download
Links For The Quadratic Equation Calculator**
12

**In The
Microsoft Excel, OpenOffice Calc, and Javascript Formats**.
13

**Number
Handling Capacity and Error Messages of**
14

**The
Quadratic Equation Calculator**
14

**The
Quadratic Equation Calculator Can Handle**.
14

**Very Large
and Very Small Numbers,**
14

**General
Error Messages Displayed by**.
16

**The
Quadratic Equation Calculator**
16

**How the
Quadratic Equation Calculator Was Created**.
16

**Creating
the Calculation Mechanism**..
16

**For The
Quadratic Equation Calculator**
16

**Additional
Features of the Quadratic Equation Calculator**
19

**Creating
the JavaScript Version of**
20

**The
Quadratic Equation Calculator**
20

**Services
Offered by the Author**
21

**Services
Offered by the Author David@TechForText.com**..
22

** **

__System Requirements
for the Downloads____,__

__And
Links____ to Obtain the Free
Downloads__

__The
Software You Need for the Downloads__

The spreadsheet versions of the
__Quadratic Equation Calculator__ require either Microsoft Excel, or the
OpenOffice.org software package. In addition, Microsoft Windows is
required for the spreadsheet versions.

The JavaScript version of the Quadratic Equation Calculator can run on any operating system that has JavaScript support, but I only tested it with Microsoft Windows. In addition, the JavaScript version requires a browser that supports JavaScript. Almost all modern operating systems and browsers support JavaScript.

__Download Links For The Quadratic
Equation Calculator__

__In
The Microsoft Excel, OpenOffice Calc, and Javascript
Formats__

** **

** **

__Note: If you do not have Microsoft Excel,
download the OpenOffice.org software package, because it is free and it is
almost as good as the Microsoft Office suite. To download go to www.OpenOffice.org or left
click on these words.__** **

** **

** **

__Number Handling
Capacity and Error Messages of__

__The
____Quadratic Equation
Calculator__

__The Quadratic Equation Calculator
Can Handle__

__Very Large and Very Small
Numbers,__

**The Quadratic Equation
Calculator**
can handle very large and very small numbers with well OVER 250 digits.
This applies to all the versions of the Calculator, except for the

When many digits are
involved the ** Quadratic Equation Calculator** in the Excel and online
JavaScript format display numbers in scientific notation. An uppercase

An example, of a large number is
10000000000000000000, and it is displayed by the __Quadratic Equation
Calculator__, in scientific notation, in this format: 1.00E+19. An
example of a very small number is 0.0000000000000000001, and it is displayed by
the Calculator in scientific notation in this format: 1.00E-19. (Note:
sometimes numbers that are extremely small are rounded to zero, by the
Calculator.)

__General Error Messages Displayed
by__

__The
Quadratic Equation Calculator__

This Calculator shows an error message when there are no solutions for the numbers that were entered. For example, if the discriminant

(b^{2}-4ac) is
negative. The calculator also shows an error message if a sub-calculation
or the values of X exceed 307 digits.

__How
____the Quadratic Equation
Calculator Was Created__

__Creating the Calculation
Mechanism__

__For The Quadratic Equation
Calculator__

The Quadratic Equation Calculator was created by using the conventional formula that people used to solve quadratic equations, and Microsoft Excel. The conventional formula is presented below:

_{}

This formula had to be converted into a format that Microsoft Excel would understand. The first step to achieve this goal was to realize that the above formula is actually two formulas in one, at least from the point of view of a computer. The two formulas are presented below:

_{}

_{}

The above formulas
were converted to a format that can be understood by Microsoft Excel, and other
spreadsheet software. How this was done can be explained in two
steps. The first is substituting cell designations for the letters in the
formula. The cell designations used are the input boxes for the values of:
**a, b, **and** c. **

The next step was to convert the implied mathematical instructions in the quadratic formulas into a format that spreadsheet software can understand. That is, for Microsoft Excel, OpenOffice Calc, and many other brands of spreadsheet software, the following notation is used:

For division, a slash: /

For multiplication, an asterisk: *

For square roots a ^ and a 0.5 are used. For example: 4^0.5 will result in a calculated result of 2

As a result of the required modifications described above the formulas were converted as follows:

_{} was changed to

=(-(F4-((F4^2)-4*F3*F5)^(0.5))*(0.5)*(1/F3))

_{} was changed to

=(-(F4+((F4^2)-4*F3*F5)^(0.5))*(0.5)*(1/F3))

The above was all
that was necessary for the basic calculation mechanism of the __Quadratic Equation
Calculator.__

__Additional Features
of____
the Quadratic Equation Calculator__

I provided a
user controllable
device to control the number of decimal places, and an error-checking mechanism
in the ** Quadratic Equation Calculator**. These features I have previously created for another
calculation device, called the

The Quadratic Equation Calculator, calculates the discriminant. To make this mechanism simply involved converting the formula

b^{2}-4ac=discriminant to
a format that can be understood by spreadsheet software. This was done in
way that is similar, but NOT identical, to the method described in the previous
subsection, (for the main calculation mechanism.)

__Creating the JavaScript Version
of____
__

__The
Quadratic Equation Calculator__

The JavaScript version of the Quadratic Equation Calculator was created from the spreadsheet version. This involves specialized software to convert Microsoft Excel to the JavaScript format. Thus, almost all of the material on this website applies to both spreadsheet and JavaScript versions.

__Services Offered by
the Author__

** **

This website was designed to
maximize efficiency and ease-of-use (usability, user-friendliness). The
text is presented with relatively large fonts. The paragraphs are short,
and the sentence structure and wording were written to maximize comprehension*.
The website has a very simple layout, on a single page, with a hyperlinked
table of contents. This makes it easy to __navigate intuitively__, by
scrolling or by left clicking on a topic or subtopic in the table of
contents. All the links for downloads and other websites are also written
with large fonts, and clearly marked as links, such as with the following words:
* left click on these words*.

Note: The material on this website is technical, and to understand every detail requires slow and careful reading. In addition, knowledge of mathematics and some familiarity with spreadsheets and computer technology is also needed for maximum comprehension. However, portions of the material, excluding the precise details, can be understood by almost anyone.

__Services Offered by
the Author David@TechForText.com__

I design and build user-friendly
software based calculation devices for __arithmetic__, __accounting__,
__currency exchange rates__,
__algebra__, __trigonometry__,
__correlations__, __calculus__, and databases with built-in calculation
devices. I also create attractive online calculation devices for
websites. I generally make these devices in the Microsoft Excel,
OpenOffice.org, and the JavaScript formats, but I can work with other
spreadsheet formats besides the above.

**For a list of websites with calculation
devices that I created, left click on these words, or go to the following
website: www.TechForText.com/Math**

I can create web communication forms for your website. This includes forms with built-in calculation devices.

I write instructions for the devices I build. I can also write instructions for software and computer devices created by others. In addition, I can write advertising for your websites, products and services.

For a list of all the services I
offer see **www.TechForText.com**

For a list of all my websites see
**www.David100.com**

My resume is online at: **www.David100.com/R**

I can provide the services
mentioned above on a fee-for-service basis, or possibly based on temporary or
permanent employment. If you are interested in my services, and want
additional contact information or more data on the services I offer, you can
email me at **David@TechForText.com
**or **use a website communication
form, by left clicking on these words.**

I am located in the USA. If you are a great distance from my locality or are in another country, this is not important. I can provide these services worldwide, because the software and websites I make can be delivered through the Internet to any locality, providing there are no governmental restrictions.

**To return to the top of this website left click on these
words**