// ----------------------------
//  ziftest.cpp
// ----------------------------
#include "ww.h"
#include "zif.h"



  class gfun : public fun
  {
	  public:
	  gfun() {}
	  double f(double x)
	  {
		  return (cos(x) - x); 
	  }
  };


 // --------------------------------------------------
	 void main()
	  {
       nl();
		 banner("Ziftest");
		 pl("f(x) = cos(x) - x");
		 nl();

		 gfun *g = new gfun();
		 precision(14);

		 double z = zef(g,0.5,0.001,1e-10);

		 pl("The zero of g is  z = ",z);
		 pl("Check:         g(z) = ",g->f(z));

		}