Quadratic Equation

Write a Java program that prints all real solutions to the quadratic equation ax2+bx+c=0. Read in a, b, c and use the quadratic formula. If the discriminate b2-4ac is negative, display a message stating that there are no real solutions.

Program Code in JAVA:

import java.io.*;

import java.math.*;

class Quad

{

public static void main(String[] args) throws Exception

{

int a,b,c,d;

float r1,r2;

System.out.println("Enter a , b & c values");

DataInputStream dis=new DataInputStream(System.in);

a=Integer.parseInt(dis.readLine());

b=Integer.parseInt(dis.readLine());

c=Integer.parseInt(dis.readLine());

d=(b*b)-(4*a*c);

if (d==0)

{

r1=r2=(float)(-b/(2*a));

System.out.println("The roots are equal\nr1="+r1+" and r2="+r2);

}

else if(d>0)

{

r1=(float)(-b+Math.sqrt(d))/(2*a);

r2=(float)(-b-Math.sqrt(d))/(2*a);

System.out.println("The roots are real & distinct\n r1="+r1+" and r2="+r2);

}

else if(d<0)

{

r1=(float)(-b/(2*a));

r2=(float)(Math.sqrt(-d)/(2*a));

System.out.println("The roots are complex &

imaginary\nr1="+r1+"+i"+r2+"\nr2="+r1+"-i"+r2);

}

}

}

Program Output:

c:\java>javac Quad.java

c:\java>java Quad

Enter a , b & c values

3 2 1

The roots are complex & imaginary

r1=0.0+i0.47140452

r2=0.0-i0.47140452