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

main()
{
	printf("sin( M_PI / 4 ) = %lf\n", sin( M_PI / 4 ));
} 


/* declared functions

	acos,	asin,	atan,	atan2,
	cos,	sin,	tan,	cosh,	sinh,	tanh,
	exp,	frexp,	idexps,	log,	log10,
	modf,	pow,	sqrt,
	ceil,	fads,	floor,	fmod,
/*

/* Some useful constants. 
M_E            2.7182818284590452354   * e *
M_LOG2E        1.4426950408889634074   * log_2 e *
M_LOG10E       0.43429448190325182765  * log_10 e *
M_LN2          0.69314718055994530942  * log_e 2 *
M_LN10         2.30258509299404568402  * log_e 10 *
M_PI           3.14159265358979323846  * pi *
M_PI_2         1.57079632679489661923  * pi2 *
M_PI_4         0.78539816339744830962  * pi4 *
M_1_PI         0.31830988618379067154  * 1pi *
M_2_PI         0.63661977236758134308  * 2pi *
M_2_SQRTPI     1.12837916709551257390  * 2sqrt(pi) *
M_SQRT2        1.41421356237309504880  * sqrt(2) *
M_SQRT1_2      0.70710678118654752440  * 1sqrt(2) *

* The above constants are not adequate for computation using `long double's.
   Therefore we provide as an extension constants with similar names as a
   GNU extension.  Provide enough digits for the 128-bit IEEE quad. 

M_El           2.7182818284590452353602874713526625L  * e *
M_LOG2El       1.4426950408889634073599246810018922L  * log_2 e *
M_LOG10El      0.4342944819032518276511289189166051L  * log_10 e *
M_LN2l         0.6931471805599453094172321214581766L  * log_e 2 *
M_LN10l        2.3025850929940456840179914546843642L  * log_e 10 *
M_PIl          3.1415926535897932384626433832795029L  * pi *
M_PI_2l        1.5707963267948966192313216916397514L  * pi2 *
M_PI_4l        0.7853981633974483096156608458198757L  * pi4 *
M_1_PIl        0.3183098861837906715377675267450287L  * 1pi *
M_2_PIl        0.6366197723675813430755350534900574L  * 2pi *
M_2_SQRTPIl    1.1283791670955125738961589031215452L  * 2sqrt(pi) *
M_SQRT2l       1.4142135623730950488016887242096981L  * sqrt(2) *
M_SQRT1_2l     0.7071067811865475244008443621048490L  * 1sqrt(2) *
*/