I'm working on this polynomial program but I have stuck at some points which still don't know what's wrong exactly. So anyway, I have to add 2 polynomials, subtracts, and multiply. So could anyone please correct this code below.

Thank you very much!!

public class Polynomial implements Cloneable {
	private int m_degree;
	private double[] m_coeff;

	public Polynomial() {
		m_degree = 0;
		m_coeff = new double[5];
	}

	// Set the x0 coefficient
	public Polynomial(double c0) {
		this();
		m_coeff[0] = c0;
	}

	// COPY CONSTRUCTOR
	public Polynomial(Polynomial source) {
		super();
		source = new Polynomial();
		source.clone();
	}

	// clone method
	public Polynomial clone() {
		Polynomial polynomial;
		try {
			polynomial = (Polynomial) super.clone();
		} catch (CloneNotSupportedException e) {
			throw new RuntimeException(
					"This class doesn't implement Cloneable ");
		}
		polynomial.m_coeff = m_coeff.clone();
		return polynomial;
	}

	// getter
	private double get(int k) {
		return (m_coeff[k]);
	}

	// setter
	public double set(int k, double coeff) {
		double oldElement = get(k);
		m_coeff[k] = coeff;
		return (oldElement);
	}

	// ADD to coefficient
	public void addToCoef(double amount, int k) {
		m_coeff[k] = amount;
		amount++;
	}

	// ASSIGN COEFFICIENT
	public void assignCoef(double newCoeff, int k) {
		m_coeff[k] = newCoeff;
	}

	// TO REMOVE
	public double remove(int k) {
		double removeElement = get(k);
		System.arraycopy(m_coeff, k - 1, m_coeff, k, degree() - k - 1);
		m_coeff[k] = m_coeff[m_degree];
		--m_degree;
		return (removeElement);
	}

	// convert to string 3.2x^0 + -2.5x^2 + 6.1x^3
	public String toString() {
		 return (coefficient(m_degree) + "x^" + m_degree + " "  + "x^" + nextTerm(m_degree) + " x^ " );
	}

	// to CLEAR
	public void clear() {
		for (int i = 0; i <= m_coeff.length; i--) {
			m_coeff[i] = 0;
		}
	}

	// To reserve
	public void reserve(int degree) {
		if (degree <= m_coeff.length) {
			throw new IllegalArgumentException("Degree is negative: " + degree);
		}
		double[] newArray = new double[degree];
		System.arraycopy(m_coeff, 0, newArray, 0, degree());
		m_coeff = newArray;
	}

	// DOUBLE COEFFICIENT
	public double coefficient(int k) {
		return m_coeff[k];
	}

	// INT DEGREE
	public int degree() {
		int degree = 1;
		if (m_coeff.length > 0) {
			for (int i = 0; i < m_coeff.length; i++) {
				if (m_coeff[i] != 0)
					degree = i;
			}
		}
		return (degree);
	}
 
	// NEXT_TERM; calling the next term of k
	public int nextTerm(int k) {
        for(int i=k;k<m_coeff.length;++i){
            if(m_coeff[i]!=0);
        }
		return -1;
	}

	// to evaluate
	public double eval(double x) {
		double p = m_coeff[m_degree];
		for (int i = 0; i < degree();  i++)
			p = m_coeff[i] + (x * p);
		return p;
	}

	// Arithmetic Operators (ADD, SUBTRACT, MULTIPLY OF TWO POLYNOMIALs
	public static Polynomial add(Polynomial p1, Polynomial p2) {
		Polynomial sum = new Polynomial();
		if(p1.degree()<=p2.degree())
        for(int i=0;i<p1.degree();i++){
            sum.reserve(i);
            sum.addToCoef(p1.coefficient(i), i);
            sum.addToCoef(p2.coefficient(i), i);
        }
    else{
        for(int i=0;i < p2.degree();i++){
            sum.reserve(i);
            sum.addToCoef(p1.coefficient(i), i);
            sum.addToCoef(p2.coefficient(i), i);
        }
    }
		return sum;
}
	
	public static Polynomial subtract(Polynomial p1, Polynomial p2) {
		Polynomial subtract = new Polynomial();
	        int i=0;
	        while(p1.nextTerm(i)!=-1||p2.nextTerm(i)!=-1){
	            subtract.assignCoef(p1.coefficient(i),i);
	            subtract.addToCoef((-1)*p2.coefficient(i), i);
	            i++;
	        }
	     
        return subtract;
	}

	public static Polynomial multiply(Polynomial p1, Polynomial p2) {
		Polynomial multiply = new Polynomial();
		for (int i = 0; i <= p1.m_degree; i++)
			for (int j = 0; j <= p2.m_degree; j++)
				multiply.m_coeff[i + j] += (p1.m_coeff[i] * p2.m_coeff[j]);
		multiply.degree();
		return multiply;
	}
	
	
	/**don't know how to start
              public static Polynomial derivative (Polynomial p1){
		 
		 return;
		 
	 }
	 **/
}

Correct it for what? You need to post specific questions or errors.

what I meant was that if I have
a) 3.4x^0 + 3x^2 + 2.5x^3
b) 4.3x^0 + 3x^2 + 4.6x^3

then add or subtract or multiply those 2 polynomials

Thanks!

And what I meant was that you need to frame specific questions or post errors that you are getting. No one is going to just "fix it" because you posted some code.