sin(2) [plan9 man page]

SIN(2)								System Calls Manual							    SIN(2)

NAME

       sin, cos, tan, asin, acos, atan, atan2 - trigonometric functions

SYNOPSIS

       #include <u.h>
       #include <libc.h>

       double sin(double x)

       double cos(double x)

       double tan(double x)

       double asin(double x)

       double acos(double x)

       double atan(double x)

       double atan2(double y, double x)

DESCRIPTION

       Sin, cos and tan return trigonometric functions of radian arguments.  The magnitude of the argument should be checked by the caller to make
       sure the result is meaningful.

       Asin returns the arc sine in the range -n/2 to n/2.

       Acos returns the arc cosine in the range 0 to n.

       Atan returns the arc tangent in the range -n/2 to n/2.

       Atan2 returns the arc tangent of y/x in the range -n to n.

SOURCE

       /sys/src/libc/port

SEE ALSO

       intro(2)

BUGS

       The value of tan for arguments greater than about 2^-31 is garbage.

																	    SIN(2)

sin(3m) 																   sin(3m)

Name
       sin, cos, tan, asin, acos, atan, atan2 - trigonometric functions and their inverses

Syntax
       #include <math.h>

       double sin(x)
       double x;

       float fsin(x)
       float x;

       double cos(x)
       double x;

       float fcos(x)
       float x;

       double tan(x)
       double x;

       float ftan(x)
       float x;

       double asin(x)
       double x;

       float fasin(x)
       float x;

       double acos(x)
       double x;

       float facos(x)
       float x;

       double atan(x)
       double x;

       float fatan(x)
       float x;

       double atan2(y,x)
       double y,x;

       float fatan2(y,x)
       float y,x;

Description
       The and functions return trigonometric functions of radian arguments x for double data types.

       The and functions return trigonometric functions for float data types.

       The and functions return the arc sine in the range -pi/2 to pi/2 for double and float data types, respectively.

       The and functions return the arc cosine in the range 0 to pi for double and float data types, respectively.

       The and functions return the arc tangent in the range -pi/2 to pi/2 for double and float data types, respectively.

       The  and  functions  return  the  arc tangent of y/x in the range -pi to using the signs of both arguments to determine the quadrant of the
       return value for double and float data types, respectively.

   Error (due to roundoff)
       When P stands for the number stored in the computer in place of pi = 3.14159 26535 89793 23846 26433 ... .  and "trig" stands  for  one	of
       "sin",  "cos"  or  "tan",  then	the  expression  "trig(x)" in a program actually produces an approximation to trig(x*pi/P), and "atrig(x)"
       approximates (P/pi)*atrig(x).  The approximations are close.

       P differs from pi by a fraction of an ulp; the difference is apparent only if the argument x is huge,  and  even  then  the  difference	is
       likely  to  be swamped by the uncertainty in x.	Every trigonometric identity that does not involve pi explicitly is satisfied equally well
       regardless of whether P = pi.  For example, sin(x)**2+cos(x)**2 = 1 and sin(2x) = 2sin(x)cos(x) to within a few ulps regardless of how  big
       x is.  Therefore, the difference between P and pi is unlikely to effect scientific and engineering computations.

Return Values
       All the double functions return NaN if NaN is passed in.

       If |x| > 1 then (x) and (x) will return the default quiet NaN.

       The function defines (0,0) = NaN.

See Also
       hypot(3m), math(3m), sqrt(3m)

								       RISC								   sin(3m)