osx man page for asin

ASIN(3) 						   BSD Library Functions Manual 						   ASIN(3)

NAME
     asin -- arc sine function

SYNOPSIS
     #include <math.h>

     double
     asin(double x);

     long double
     asinl(long double x);

     float
     asinf(float x);

DESCRIPTION
     The asin() function computes the principal value of the arc sine of x.  The result is in the range [-pi/2, +pi/2].

SPECIAL VALUES
     asin(+-0) returns +-0.

     asin(x) returns a NAN and raises the "invalid" floating-point exception for |x| > 1.

VECTOR OPERATIONS
     If you need to apply the asin() function to SIMD vectors or arrays, using the following functions provided by the Accelerate.framework may
     give significantly better performance:

     #include <Accelerate/Accelerate.h>

     vFloat vasinf(vFloat x);
     void vvasinf(float *y, const float *x, const int *n);
     void vvasin(double *y, const double *x, const int *n);

SEE ALSO
     acos(3), atan(3), atan2(3), cos(3), cosh(3), sin(3), sinh(3), tan(3), tanh(3), math(3)

STANDARDS
     The asin() function conforms to ISO/IEC 9899:2011.

BSD
								 December 11, 2006							       BSD