Quadratic Equation
The form of the
quadratic equation is ax² + bx + c = 0 where a, b and c are real and a !=0, x
is an unknown variable. The nature of roots is determined by the discriminant.
The formula to find the
roots of the quadratic is
Java Program to Find all Roots of a Quadratic equation
discriminant = (b * b) - (4 * a * c). After check
1. if discriminant > 0 then
The roots are unequal and irrational
2. if discriminant = 0 then
The roots are equal and rational
3 otherwise
The roots are imaginary
import java.util.*;
class QuadraticEquation
{
public static void main(String args[])
{
double a, b, c;
double root, root1, root2;
double disc; // discriminant
Scanner sc=new Scanner(System.in);
System.out.println("Enter value of
a, b, c");
a= sc.nextInt();
b= sc.nextInt();
c= sc.nextInt();
// Calculate
disc = (b * b) - (4 * a * c);
if ( disc > 0 )
{
root1 = (- b + Math.sqrt(disc)) /
(2 * a);
root2 = (- b - Math.sqrt(disc)) /
(2 * a);
System.out.println("The roots are
unequal and irrational " + root1 + " and " + root2);
}
else if ( disc == 0 )
{
root = - b / (2 * a);
System.out.println("The roots
are equal and rational " + root + " and " + root );
}
else if ( disc < 0 )
{
System.out.println("The roots
are imaginary");
}
} // function is over
} // class is over
Output
Enter
value of a, b, c
20
30
20
The
roots are imaginary
Enter
value of a, b, c
2
7
3
The
roots are unequal and irrational -0.5 and -3.0
Java program to find the Roots of Quadratic equation with method
class
QuadraticEquationWithMethod
{
double a, b, c;
double disc; // discriminant
double root, root1, root2;
// quadratic equation method
void quadraticEquation(double x, double y,
double z)
{
a = x;
b = y;
c = z;
disc = (b * b) - (4 * a * c);
if ( disc > 0 )
{
root1 = (- b + Math.sqrt(disc)) /
(2 * a);
root2 = (- b - Math.sqrt(disc)) /
(2 * a);
System.out.println("The roots
are unequal and irrational " + root1 + " and " + root2);
}
else if ( disc == 0 )
{
root = - b / (2 * a);
root1 = root;
System.out.println("The roots
are equal and rational " + root + " and " + root1 );
}
else if ( disc < 0 )
{
System.out.println("The roots
are imaginary");
}
}
// main method
public static void main(String args[])
{
double a, b, c;
Scanner sc=new Scanner(System.in);
System.out.println("Enter value of
a, b, c");
a= sc.nextInt();
b= sc.nextInt();
c= sc.nextInt();
QuadraticEquationWithMethod ob=new
QuadraticEquationWithMethod();
// calling method
ob.quadraticEquation(a, b, c);
} // main method is over
} //
class is over
Output:
Enter value of a, b, c
1
1
1
The
roots are imaginary
Enter
value of a, b, c
1
6
11
The
roots are imaginary
Enter
value of a, b, c
1
7
12
The
roots are unequal and irrational -3.0 and -4.0
