casin(3)                   Library Functions Manual                   casin(3)

NAME
       casin, casinf, casinl - complex arc sine

LIBRARY
       Math library (libm, -lm)

SYNOPSIS
       #include <complex.h>

       double complex casin(double complex z);
       float complex casinf(float complex z);
       long double complex casinl(long double complex z);

DESCRIPTION
       These functions calculate the complex arc sine of z.  If y = casin(z),
       then z = csin(y).  The real part of y is chosen in the interval
       [-pi/2,pi/2].

       One has:

           casin(z) = -i clog(iz + csqrt(1 - z * z))

ATTRIBUTES
       For an explanation of the terms used in this section, see
       attributes(7).

       +--------------------------------------------+---------------+---------+
       |Interface                                   | Attribute     | Value   |
       +--------------------------------------------+---------------+---------+
       |casin (), casinf (), casinl ()              | Thread safety | MT-Safe |
       +--------------------------------------------+---------------+---------+
STANDARDS
       C11, POSIX.1-2008.

HISTORY
       glibc 2.1.  C99, POSIX.1-2001.

SEE ALSO
       clog(3), csin(3), complex(7)

Linux man-pages 6.7               2023-10-31                          casin(3)