asin(3) - Linux man page

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.

Description

The asin() function calculates the arc sine of x; that is the value whose sine is x. If x falls outside the range -1 to 1, asin() fails and errno is set.

Return Value

The asin() function returns the arc sine in radians and the value is mathematically defined to be between -PI/2 and PI/2 (inclusive).

Errors

EDOM: x is out of range.

Conforming to

SVr4, POSIX.1-2001, 4.3BSD, C89. The float and long double variants are C99 requirements.