#include <math.h>
#include <stdio.h>

double integra(double (*fun)(double),double min,double max,int n)
{
  double somma=0, x;
  double passo=(max-min)/n;
  somma += ((*fun)(min)+(*fun)(max))/2.;
  for ( x=min+passo ; x<max ; x+=passo ) 
    {
      somma += fun(x);
    }
  somma *= passo;
  return (somma);
}

int main() {
  double x1=0., x2=1.;
  printf("L'integrale del seno tra 0 e 1 e': ");
  printf("%f (%f)\n",integra(sin,x1,x2,100),1.-cos(1.));
  return 0;
}