29. PHP Program to find the roots of the given Quadratic Equation.
How does this program work?
- In this program you are going to learn about how to find roots of the given quadratic equation using PHP.
-
The term b2-4ac is known as the discriminant of a quadratic equation. The discriminant tells the nature of the roots.
- If discriminant is greater than 0, the roots are real and different.
- If discriminant is equal to 0, the roots are real and equal.
- If discriminant is less than 0, the roots are complex and different.
- In this program, library function sqrt() is used to find the square root of a number.
Here is the code
<html>
<head>
<title> PHP Program To find the roots of the given Quadratic Equation</title>
</head>
<body>
<form method="post">
<table border="0">
<tr>
<td> <input type="text" name="num1" value="" placeholder="Enter 1st value"/> </td>
</tr>
<tr>
<td> <input type="text" name="num2" value="" placeholder="Enter 2nd value"/> </td>
</tr>
<tr>
<td> <input type="text" name="num3" value="" placeholder="Enter 3rd value"/> </td>
</tr>
<tr>
<td> <input type="submit" name="submit" value="Submit"/>
</td> </tr>
</table>
</form>
<?php
if(isset($_POST['submit']))
{
$a = $_POST['num1'];
$b = $_POST['num2'];
$c = $_POST['num3'];
$precision = 4;
$d = $b * $b - 4 * $a * $c; // Discriminant of a quadratic equation
if($d < 0) {
echo " Roots are complex numbers. " ;
echo " Roots of quadratic equation are: " ;
echo -$b/(2*$a). " + " .number_format(sqrt(-$d)/(2*$a), $precision)."i ";
echo ", ". -$b/(2*$a).number_format(-sqrt(-$d)/(2*$a), $precision)."i" ;
}
else if($d == 0) {
echo "Both roots are equal.";
$root1 = -$b /(2* $a);
echo"Root of quadratic equation is: " .$root1 ;
return 0;
}
else
{
echo "Roots are real numbers.";
$root1 = ( -$b + sqrt($d)) / (2* $a );
$root2 = ( -$b - sqrt($d)) / (2* $a);
echo "Roots of quadratic equation are: " .$root1 .$root2 ;
}
return 0;
}
?>
</body>
</html>
