Linux manual pages Section 3  

Name

cacosh, cacoshf, cacoshl — complex arc hyperbolic cosine

Synopsis

#include <complex.h>
double complex cacosh( double complex z);
 
float complex cacoshf( float complex z);
 
long double complex cacoshl( long double complex z);
 
[Note] Note

Link with −lm.

DESCRIPTION

The cacosh() function calculates the complex arc hyperpolic cosine of z. If y = cacosh(z), then z = ccosh(y). The imaginary part of y is chosen in the interval [−pi,pi]. The real part of y is chosen nonnegative.

One has:

    cacosh(z) = 2 * clog(csqrt((z + 1) / 2) + csqrt((z − 1) / 2))

VERSIONS

These functions first appeared in glibc in version 2.1.

CONFORMING TO

C99.

EXAMPLE

/* Link with "−lm" */

#include <complex.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>

int
main(int argc, char *argv[])
{
    double complex z, c, f;

    if (argc != 3) {
        fprintf(stderr, "Usage: %s <real> <imag>\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    z = atof(argv[1]) + atof(argv[2]) * I;

    c = cacosh(z);
    printf("cacosh() = %6.3f %6.3f*i\n", creal(c), cimag(c));

    f = 2 * clog(csqrt((z + 1)/2) + csqrt((z − 1)/2));
    printf("formula  = %6.3f %6.3f*i\n", creal(f2), cimag(f2));

    exit(EXIT_SUCCESS);
}

SEE ALSO

acosh(3), cabs(3), ccosh(3), cimag(3), complex(7)

COLOPHON

This page is part of release 3.33 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://man7.org/linux/man-pages/.


  Copyright 2002 Walter Harms(walter.harmsinformatik.uni-oldenburg.de)
and Copyright (C) 2011 Michael Kerrisk <mtk.manpagesgamil.com>
Distributed under GPL