CASIN(3)                                                                Linux Programmer's Manual                                                               CASIN(3)

NAME
       casin, casinf, casinl - complex arc sine

SYNOPSIS
       #include <complex.h>

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

       Link with -lm.

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))

VERSIONS
       These functions first appeared in glibc in version 2.1.

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

       ┌──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │Interface                                                                                                                             │ Attribute     │ Value   │
       ├──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │casin(), casinf(), casinl()                                                                                                           │ Thread safety │ MT-Safe │
       └──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

CONFORMING TO
       C99, POSIX.1-2001, POSIX.1-2008.

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

                                                                               2021-03-22                                                                       CASIN(3)