NEED HELP ASAP JAVA CODE

Question

Quadratic equations ax² + bx + c = 0. Class consists of:

1. private data fields a, b,c that represent 3 coeffiecients
2. no org constructor
3. 3 arg constructor
4. 3 getter methods for a,b,c
5. a method name GetDiscriminate() that returns the discriminant - b²-4ac
6. method names getRoot1() and getROOT2() for returning 2 roots of the equations

EQUATIONS: r1 = -b + squareroot discriminant

—————————————

2a

r2 = -b + squareroot discriminant

—————————————

2a

Both method should return as 0 if discriminant is negative

1. use Exception handling in all the setter methods
2. method toString() - to represent the state of the object. If discriminant is positive, display two roots. If 0 then 1 root. if not, then "the equation has no real roots"
3. method equals() - to compare 2 objects for equality
4. write a client that prompts the user iteratively to enter values for a,b,c and display results on discriminant. program should end if the user enters 0 for a.

Answer 1

import java.lang.Exception;

import java.io.*;

class IllegalArgumentException extends Exception { IllegalArgumentException( String msg) { super(msg); } }

class QuadraticEquation

{

private double A;

private double B;

private double C;

private double discriminant;

private void calcDiscriminant() { discriminant = B*B-4*A*C; }

//defaults to the parent quadratic function y=x^2

public QuadraticEquation()

{

A=1; B=C=0;

this.calcDiscriminant();

}

public QuadraticEquation(double a, double b, double c) throws IllegalArgumentException

{

if (a==0)

{

A=1; B=C=0;

this.calcDiscriminant();

throw (new IllegalArgumentException("A is not zero"));

}

else

{

A=a; B=b; C=c;

this.calcDiscriminant();

}

}

public void SetA( double a) throws IllegalArgumentException

{

if (a==0)

{

A=1; B=C=0;

throw (new IllegalArgumentException("A is not zero"));

}

else

{

A=a;

this.calcDiscriminant();

}

}

public void SetB( double b) { B=b; calcDiscriminant(); }

public void SetC( double c) { C=c; calcDiscriminant(); }

public double GetA() { return(A); }

public double GetB() { return(B); }

public double GetC() { return(C); }

public double GetDiscriminant() { return(discriminant); }

public double f( double x) { return(A*x*x+B*x+C); }

public double yIntercept() { return(this.f(0)); }

public double symmetryAxis() { return( -B/(2*A)); }

public boolean Equals( QuadraticEquation quadEq)

{

return ((this.A == quadEq.GetA()) && (this.B==quadEq.GetB()) && (this.C==quadEq.GetC()));

}

public QuadraticEquation( QuadraticEquation quadEq)

{

this.A = quadEq.GetA();

this.B=quadEq.GetB();

this.C = quadEq.GetC();

this.calcDiscriminant();

}

public String toString()

{

return(

new String(

"A= " + this.A

+ " : B= " + this.B

+ " : C = " + this.C

+ " : discriminant = " + this.discriminant

)

);

}

public String GetRoot1()

{

String strReturn;

double root1=0;

if (discriminant>0)

{

root1 = ((-B + Math.sqrt(discriminant))/(2*A));

strReturn = Double.toString(root1);

}

else if (discriminant==0)

{

root1 = (-B)/(2*A);

strReturn = Double.toString(root1);

}

else

{

double realPart = (-B)/(2*A);

double imaginaryPart = Math.sqrt(-discriminant)/(2*A);

strReturn = Double.toString(realPart)+ "+" + Double.toString(imaginaryPart)+"i";

}

return(strReturn);

}

public String GetRoot2()

{

String strReturn;

double root2=0;

if (discriminant>0)

{

root2 = ((-B - Math.sqrt(discriminant))/(2*A));

strReturn = Double.toString(root2);

}

else if (discriminant==0)

{

root2 = (-B)/(2*A);

strReturn = Double.toString(root2);

}

else

{

double realPart = (-B)/(2*A);

double imaginaryPart = Math.sqrt(-discriminant)/(2*A);

strReturn = Double.toString(realPart)+ "-" + Double.toString(imaginaryPart)+"i";

}

return(strReturn);

}

public static void main(String args[])

{

Console console = System.console();

double A,B,C;

String inbuff;

try

{

do

{

System.out.print(" Please input A :> ");

inbuff = console.readLine();

A = Double.parseDouble(inbuff);

}

while (A==0);

System.out.print(" Please input B :> ");

inbuff = console.readLine();

B = Double.parseDouble(inbuff);

System.out.print(" Please input C :> ");

inbuff = console.readLine();

C = Double.parseDouble(inbuff);

QuadraticEquation quadraticEquation = new QuadraticEquation(A,B,C);

System.out.println(quadraticEquation.toString());

double discr = quadraticEquation.GetDiscriminant();

String rootSoln1 = quadraticEquation.GetRoot1();

String rootSoln2 = quadraticEquation.GetRoot2();

if (discr>0)

{

System.out.println(" the two real solutions are " + Double.parseDouble(rootSoln1)

+ " and " + Double.parseDouble(rootSoln2));

}

else if (discr==0)

{

System.out.println(" the only solution is " + Double.parseDouble(rootSoln1)

+ " and " + Double.parseDouble(rootSoln2) + " has multiplicity 2 , is a double solution");

}

else

{

System.out.println(" the two imaginary/complex solutions are " + rootSoln1 + " and " + rootSoln2);

}

}

//catch(IOException ex) { System.out.println(" IO Exception occurs on input "); }

catch(IllegalArgumentException ex) { System.out.println(" Illegal argument exception occurs "); }

}

}