NAME¶

asin, asinf, asinl - arc sine function

SYNOPSIS¶

#include <math.h>

double asin(double x);
 
float asinf(float x);
 
long double asinl(long double x);

Link with -lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
asinf(), asinl():

DESCRIPTION¶

The asin() function calculates the principal value of the arc sine of x; that is the value whose sine is x.

RETURN VALUE¶

On success, these functions return the principal value of the arc sine of x in radians; the return value is in the range [-pi/2, pi/2]. If x is a NaN, a NaN is returned. If x is +0 (-0), +0 (-0) is returned. If x is outside the range [-1, 1], a domain error occurs, and a NaN is returned.

ERRORS¶

See math_error(7) for information on how to determine whether an error has occurred when calling these functions. The following errors can occur:

Domain error: x is outside the range [-1, 1]

errno is set to EDOM. An invalid floating-point exception (FE_INVALID) is raised.

CONFORMING TO¶

C99, POSIX.1-2001. The variant returning double also conforms to SVr4, 4.3BSD, C89.

SEE ALSO¶

acos(3), atan(3), atan2(3), casin(3), cos(3), sin(3), tan(3)

COLOPHON¶

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