/*
 * Compute sigma f(x)^2, x=xm,...,xn
 * f(x) is passed as a parameter
 */

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

double sum_square(double (*f)(double), int m, int n)
{
  int k;
  double sum = 0.0;

  for (k = m; k <= n; ++k)
    sum += f(k) * f(k);
  return sum;
}

double f(double x)
{
  return 1.0 / x;
}

int main(void)
{
  printf("%s%.7f\n%s%.7f\n",
         " First computation: ", sum_square(sin, 2, 13),
         "Second computation: ", sum_square(f, 1, 10000));
  return 0;
}