# csin.3   [plain text]

```.\" Copyright (c) 2006 Apple Computer
.\"
.Dd November 9, 2006
.Dt CSIN 3
.Os BSD 4
.Sh NAME
.Nm csin
.Nd complex sine function
.br
.Nm ccos
.Nd complex cosine function
.br
.Nm ctan
.Nd complex tangent function
.Sh SYNOPSIS
.Fd #include <complex.h>
.Ft double complex
.Fn csin "double complex z"
.Ft long double complex
.Fn csinl "long double complex z"
.Ft float complex
.Fn csinf "float complex z"
.Ft double complex
.Fn ccos "double complex z"
.Ft long double complex
.Fn ccosl "long double complex z"
.Ft float complex
.Fn ccosf "float complex z"
.Ft double complex
.Fn ctan "double complex z"
.Ft long double complex
.Fn ctanl "long double complex z"
.Ft float complex
.Fn ctanf "float complex z"
.Sh DESCRIPTION
.Fn csin "z"
computes the sine of the complex floating-point number
.Fa z .
.Pp
.Fn ccos "z"
computes the cosine of the complex floating-point number
.Fa z .
.Pp
.Fn ctan "z"
computes the tangent of the complex floating-point number
.Fa z .
.Sh NOTES
csin, ccos, and ctan are defined in terms of the complex hyperbolic functions as follows:
.Bd -literal -offset indent
csin(z) = -i * csinh(i*z),
.br
ccos(z) = ccosh(i*z),
.br
ctan(z) = -i * ctanh(i*z).
.Ed