Polynomial.java

public class Polynomial {
  public double[] coeff = new double[100];

  public Polynomial() {
    coeff[0] = 0.0;
  }

  public Polynomial(double[] arr) {
    coeff = arr;
  }

  public Polynomial add(Polynomial b) {
    // Adds two polynomials
    double[] newq = new double[100];
    double[] larger = b.coeff.clone();
    double smaller[] = coeff;
    int size = b.coeff.length;

    if (size < coeff.length) {
      size = coeff.length;
      larger = coeff.clone();
      smaller = b.coeff.clone();
    }

    for (int i = 0; i < size - 1; i++) {
      newq[i] = larger[i];
    }
    for (int i = 0; i < size - 1; i++) {
      newq[i] += smaller[i];
    }
    Polynomial c = new Polynomial(newq);
    return c;
  }

  public double evaluate(double x) {
    // Evaluates polynomial
    double result = 0;
    double temp = 0;
    for (int i = 0; i < coeff.length - 1; i++) {
      temp = Math.pow(x, i);
      result += coeff[i] * temp;
    }
    return result;
  }

  public boolean hasRoot(double x) {
    return evaluate(x) == 0;
  }
}