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Quadratic Equation Calculator

This free javascript calculator is used for quadratic calculation based on quadratic equation. This Quadratic calculator is for free.

Features

Javascript Quadratic calculator calculates the roots for given co-ordinates.
This is a free javascript calculator.
Just copy the code into your page and use it.

Preview

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Downloads

Javascript Code

<script type="text/javascript">
function quad()
{
var a=document.getElementById("av").value;
var b=document.getElementById("bv").value;
var c=document.getElementById("cv").value;
var d=(Math.pow(b,2)-(4*a*c));
var x1=(-b + Math.sqrt(d)) / (2*a);
var x2=(-b - Math.sqrt(d)) / (2*a);
document.getElementById("r1").value=x1;
document.getElementById("r2").value=x2;
if(document.getElementById("r1").value == "NaN")
document.getElementById("r1").value="imag";
if(document.getElementById("r2").value == "NaN")
document.getElementById("r2").value="imag";
}
var check=true;
function isNumberKey(id)
{var no=eval('"'+id+'"');var number= document.getElementById(no).value;if(number.length==1){
check=true;}if(number.length>1){
var dd = number;
if(dd.substring(dd.length,(dd.length-1))=='-')
{
if(check)
{
check=false;
}
else
{
dd = dd.substring(0,(dd.length-1));
document.getElementById(no).value = dd;
}
}}if(!number.match(/^[0-9-]+$/) && number !=""){document.getElementById(id).value="";document.getElementById(id).focus();}else{
var dd = number;if(dd.substring(dd.length,(dd.length-1))=='-'){
if(check)
{
check=false;
}
else
{
document.getElementById(id).value="";
document.getElementById(id).focus();
}}
}
}
</script>

HTML Code

<form name="qfrm">
<table>
<tr>
<td><input type="text" name="av" id="av" size="3" onkeyup="isNumberKey(this.id)">x<sup>2</sup>+</td>
<td><input type="text" name="bv" id="bv" size="3" onkeyup="isNumberKey(this.id)">x+</td>
<td><input type="text" name="cv" id="cv" size="3" onkeyup="isNumberKey(this.id)"></td></tr>
<tr rowspan="2"><td colspan="3" align="center"><input type="button" value="Calculate" onclick="quad()"></td></tr>
</table>
<table>
<tr rowspan="2"><td colspan="3" align="center">Result</td></tr>
<tr><td>Root 1<input type="text" name="r1" id="r1" size="10" readonly></td>
<td>Root 2<input type="text" name="r2" id="r2" size="10" readonly></td></tr>
</table>
</form>

Release Date - 07-04-2008
Get free version without ©copyright link for just 10ドル/-
For customization of this script or any script development, mail to support@hscripts.com

Usage

Just follow the below instructions to have your own Quadratic Calculator.
Copy the HTML code given above,save it with .html extension.
Just copy and paste the javascript code given above in <head> section of HTML file.
Run the file in any web browser, to have your own Quadratic calculator.