ASIN(3) | Library Functions Manual | ASIN(3)

# NAME

`asin`, `asinf`, `asinl` — arc sine functions

# SYNOPSIS

Math Library (libm, -lm)
`#include <math.h>`

double
`asin`(double x);

float
`asinf`(float x);

long double
`asinl`(long double x);

# DESCRIPTION

The `asin`() function computes the principal value of the arc sine of x in the range [-pi/2, +pi/2]. The `asinf`() function is a single precision version of `asin`(). The `asinl`() function is an extended precision version of `asin`().

# RETURN VALUES

If |x|>1, `asin`(x), `asinf`(x) and `asinl`(x) return NaN and set the global variable errno to `EDOM`.

# SEE ALSO

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

June 7, 2025 | Debian