// ................................................................... #include
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <corso.h>

// .............................................................. dichiarazioni
double funz(double x);

// ...................................................................... main
main()
{
  int i;
  double x,x1,x2;
  double (*ptfunz)(double x);

  ptfunz=funz;
  x1=3.0;
  x2=4.0;
  bracket(&x1,&x2,ptfunz);
  x=bisection(x1,x2,1.0e-6,ptfunz);
  printf("la soluzione e' %.7le\n",x);
}

// .......................................................................funz
double funz(double x)
{
  double y;

  y=15.0*pow(x,3.0)+12.0*pow(x,2.0);
  return y;
}