casin(3) Library Functions Manual casin(3) casin, casinf, casinl - (libm, -lm) #include double complex casin(double complex z); float complex casinf(float complex z); long double complex casinl(long double complex z); z. y = casin(z), z = csin(y). y [-pi/2,pi/2]. : casin(z) = -i clog(iz + csqrt(1 - z * z)) attributes(7). +----------------------------+----------------------------------------------------------+--------------------------+ | | | | +----------------------------+----------------------------------------------------------+--------------------------+ |casin(), casinf(), casinl() | | MT-Safe | +----------------------------+----------------------------------------------------------+--------------------------+ C11, POSIX.1-2008. glibc 2.1. C99, POSIX.1-2001. clog(3), csin(3), complex(7) () Azamat Hackimov , Dmitriy S. Seregin , Dmitry Bolkhovskikh , Katrin Kutepova , Yuri Kozlov ; GNU (GNU General Public License - GPL, 3 ) , - . - , , () () () . Linux man-pages 6.18 8 2026 . casin(3)