CCOS(3) | Library Functions Manual | CCOS(3)

# NAME

`ccos`, `ccosf`, `ccosl` — complex circular cosine

# SYNOPSIS

Math Library (libm, -lm)
`#include <complex.h>`

double complex
`ccos`(double complex z);

float complex
`ccosf`(float complex z);

long double complex
`ccosl`(long double complex z);

# DESCRIPTION

The `ccos`(), `ccosf`() and `ccosl`() functions compute the complex circular cosine of z.

If z = x + iy, then

    ccos(z) = cos(x) cosh(y) - i sin(x) sinh(y).

# RETURN VALUES

The `ccos`(), `ccosf`() and `ccosl`() functions return the complex circular cosine of z.

# SEE ALSO

csin(3), ctan(3)

# STANDARDS

The `ccos`(), `ccosf`() and `ccosl`() functions conform to ISO/IEC 9899:1999 (“ISO C99”).

June 7, 2025 | Debian