#include <iostream>
#include "math.h"

double
bisect(double kl, double kr, double k);

double f(double x, double k)
{
  double W = 1;
  return(cos(x) + W*sin(x)/x-cos(k));
}


int
main()
{
  int N = 200;
  double pi = acos(-1);

  for(int i = 0; i < N; i++){
    double k = -pi+2*pi/N*i;

    double step = 0.002;
    for(double k2 = -00; k2 <= 20; k2+=step){
      double k_solution = bisect(k2, k2+step, k);
      if(k_solution != 99999)
        std::cout << k << " " << k_solution << " " << k2*k2/2. << std::endl;
    }
  }
}

double
bisect(double kl, double kr, double k)
{
  double ret_val = 99999;
  double tol = 1.e-8;

  if(f(kl,k)*f(kr,k) > 0) return ret_val;

  while(true){
    double km = (kl+kr)/2.;
    if(f(km,k)*f(kl,k) < 0)
      kr = km;
    else
      kl = km;

//    std::cout << kl << " " << kr << " " << fabs(kl-kr) << std::endl;

    if(fabs(kl-kr) < tol) break;
  }

  ret_val = kl;
  return ret_val;
}