casin(3) Library Functions Manual casin(3)

casin, casinf, casinl - complex arc sine

Math library (libm, -lm)

#include <complex.h>
double complex casin(double complex z);
float complex casinf(float complex z);
long double complex casinl(long double complex z);

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))

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

Interface Attribute Value
casin (), casinf (), casinl () Thread safety MT-Safe

C11, POSIX.1-2008.

glibc 2.1. C99, POSIX.1-2001.

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

2023-07-20 Linux man-pages 6.05.01