/* Sine.c: sine function approximation	*/
/* author: Weiwei Chen			*/
/* date: Oct. 10. 2010			*/

#include <stdio.h> 


/* main function */
int main(void)
{
	/* variable definitions */
	long double x, y, x2, x3;

	/* input section */
	printf("Please enter the real value x (in radians): ");
	scanf("%Lf", &x);
	
	/* computation section */
	x2 = x * x;
	x3 = x2 * x;

	/*y = x - (x*x*x)/(3.0*2.0*1.0)
	      + (x*x*x*x*x)/(5.0*4.0*3.0*2.0*1.0);*/
	y = x - (x2 * x) / (3.0*2.0*1.0)
	      + (x2*x3)/(5.0*4.0*3.0*2.0*1.0);

	/* output section */
	printf("sin %Lf is approximately %Lf\n", x, y);

	/* exit */
	return 0;
}	/* end of main */

/* EOF */