<script
language="javascript"
type="text/javascript">
var
rootparti;
var
rootpart;
var
det;
var
rootparti1;
var
rootparti2;
var
a;
var
b;
var
c;
var
x1;
var
x2;
var
i =
"i";
function
checkQuad()
{
var
a =
document.fquad.fa.value;
var
b =
document.fquad.fb.value;
var
c =
document.fquad.fc.value;
if
(a
==
0
&&
c !=
0)
{
x1
=
-c
/
b;
x2
=
"Not a quadratic equation, but
here is your answer for x";
document.fquad.x1.value=x1;
document.fquad.x2.value=x2;
}
else
if
(a
==
""
&&
c !=
0)
{
x1
=
-c
/
b;
x2
=
"Not a quadratic equation";
document.fquad.x1.value=x1;
document.fquad.x2.value=x2;
}
else
{
quad();
}
}
function
quad()
{
var
a =
document.fquad.fa.value;
var
b =
document.fquad.fb.value;
var
c =
document.fquad.fc.value;
det
=
Math.pow(b,2)
-
4
*
a *
c;
rootpart
=
Math.sqrt(det)
/
(2
*
a);
rootparti
=
(Math.sqrt(-det)
/
(2
*
a))
+
i;
if
(parseFloat(rootparti)
<
0)
{
rootparti1
=
rootparti;
rootparti2
=
(-1
*
parseFloat(rootparti))
+
i;
}
else
{
rootparti1
=
(-1
*
parseFloat(rootparti))
+
i;
rootparti2
=
rootparti;
}
if
(rootparti1
==
"1i")
{
rootparti1
=
i;
rootparti2
=
"-i";
}
else
if
(rootparti1
==
"-1i")
{
rootparti1
=
"-i";
rootparti2
=
i;
}
if
(det
==
0)
{
x1
=
x2 =
-b
/
(2
*
a);
}
else
if
(det
>
0)
{
x1
=
(-b
+
Math.sqrt(det))
/
(2
*
a);
x2
=
(-b
-
Math.sqrt(det))
/
(2
*
a);
}
else
if
((-b
/
(2
*
a))
==
0)
{
x1
=
rootparti1;
x2
=
rootparti2;
}
else
{
x1
=
(-b
/
(2
*
a)
+
" + "
+
rootparti1);
x2
=
(-b
/
(2
*
a)
+
" + "
+
rootparti2);
}
document.fquad.x1.value=x1;
document.fquad.x2.value=x2;
}
</script>
<form
name=fquad>
<table>
<tr>
<td>
<h2>
<input
name=fa
size=4>
x<SUP>2</SUP>+
<input
name=fb
size=4>
x + <input
name=fc
size=4>
= 0
<input
type=button
value="Solve"
onClick="checkQuad()">
<input
type=reset
value="Reset">
</h2>
</td>
</tr>
<tr>
<td>
<h2>
x<sub>1</sub>=<input
name=x1
size=45>
<br>
x<sub>2</sub>=
<input
name=x2
size=45>
</h2>
</td>
</tr>
</table>
</form>
