CACOSH

Section: Linux Programmer's Manual (3)
Updated: 2015-04-19
Index Return to Main Contents
 

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);

Link with -lm.  

DESCRIPTION

These functions calculate the complex arc hyperbolic 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.  

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).
InterfaceAttributeValue
cacosh(), cacoshf(), cacoshl() Thread safetyMT-Safe
 

CONFORMING TO

C99, POSIX.1-2001, POSIX.1-2008.  

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

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Index

NAME
SYNOPSIS
DESCRIPTION
VERSIONS
ATTRIBUTES
CONFORMING TO
EXAMPLE
SEE ALSO
COLOPHON

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Time: 06:54:09 GMT, September 21, 2018