```/* nag_quad_1d_fin_smooth (d01bdc) Example Program.
*
* NAGPRODCODE Version.
*
* Copyright 2016 Numerical Algorithms Group.
*
* Mark 26, 2016.
*/

#include <stdio.h>
#include <math.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nagd01.h>
#include <nagx01.h>

#ifdef __cplusplus
extern "C"
{
#endif
static double NAG_CALL f(double x, Nag_Comm *comm);
#ifdef __cplusplus
}
#endif

int main(void)
{
static double ruser[1] = { -1.0 };
Integer exit_status = 0;
double a, abserr, b, epsabs, epsrel, result;
Nag_Comm comm;

/* For communication with user-supplied functions: */
comm.user = ruser;

/* Skip heading in data file */
scanf("%*[^\n] ");
/* Input arguments */
scanf("%lf %lf", &epsabs, &epsrel);
scanf("%lf %lf", &a, &b);

*/
nag_quad_1d_fin_smooth(f, a, b, epsabs, epsrel, &result, &abserr, &comm);

printf("\na      - lower limit of integration = %10.4f"
"\nb      - upper limit of integration = %10.4f"
"\nepsabs - absolute accuracy requested = %9.2e"
"\nepsrel - relative accuracy requested = %9.2e\n"
"\nresult - approximation to the integral = %9.5f"
"\nabserr - estimate to the absolute error = %9.2e\n\n",
a, b, epsabs, epsrel, result, abserr);
if (abserr > MAX(epsabs, epsrel * fabs(result)))
printf("Warning - requested accuracy may not have been achieved.\n");

return exit_status;
}

static double NAG_CALL f(double x, Nag_Comm *comm)
{
if (comm->user[0] == -1.0) {
printf("(User-supplied callback f, first invocation.)\n");
comm->user[0] = 0.0;
}
return (pow(x, 2)) * sin(10.0 * nag_pi * x);
}
```