```/* nag_interval_zero_cont_func (c05avc) Example Program.
*
* Copyright 2017 Numerical Algorithms Group.
*
* Mark 26.2, 2017.
*/

#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <math.h>
#include <nagc05.h>

int main(void)
{
/* Scalars */
Integer exit_status = 0;
double boundl, boundu, fx, h, x, y;
Integer ind;
/* Arrays */
double c[11];
NagError fail;

INIT_FAIL(fail);

printf("nag_interval_zero_cont_func (c05avc) Example Program Results\n");

x = 3.0;
h = 0.1;
boundl = 0.0;
boundu = 4.0;
ind = 1;
fx = 0.0;
/* nag_interval_zero_cont_func (c05avc).
* Locates an interval containing a simple zero of a continuous
* function using binary search and reverse communication.
*/
while (ind != 0) {
nag_interval_zero_cont_func(&x, fx, &h, boundl, boundu, &y, c, &ind,
&fail);

if (ind != 0)
fx = pow(x, 2) - 3.0 * x + 2.0;
}

if (fail.code == NE_NOERROR) {
printf("Interval containing root is [x,y], where\n");
printf("x = %12.4f, y = %12.4f\n", x, y);
printf("Values of f at x and y are\n");
printf("f(x) = %12.2f, f(y) = %12.2f\n", fx, c[0]);
}
else {
printf("%s\n", fail.message);
exit_status = 1;
goto END;
}

END:
return exit_status;
}
```