cacoshl(3)

1CACOSH(3)                  Linux Programmer's Manual                 CACOSH(3)
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NAME

6       cacosh, cacoshf, cacoshl - complex arc hyperbolic cosine
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SYNOPSIS

9       #include <complex.h>
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11       double complex cacosh(double complex z);
12       float complex cacoshf(float complex z);
13       long double complex cacoshl(long double complex z);
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15       Link with -lm.
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DESCRIPTION

18       The  cacosh()  function calculates the complex arc hyperpolic cosine of
19       z.  If y = cacosh(z), then z = ccosh(y).  The imaginary part  of  y  is
20       chosen in the interval [-pi,pi].  The real part of y is chosen nonnega‐
21       tive.
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23       One has:
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25           cacosh(z) = 2 * clog(csqrt((z + 1) / 2) + csqrt((z - 1) / 2))
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VERSIONS

28       These functions first appeared in glibc in version 2.1.
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CONFORMING TO

31       C99.
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EXAMPLE

34       /* Link with "-lm" */
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36       #include <complex.h>
37       #include <stdlib.h>
38       #include <unistd.h>
39       #include <stdio.h>
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41       int
42       main(int argc, char *argv[])
43       {
44           double complex z, c, f;
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46           if (argc != 3) {
47               fprintf(stderr, "Usage: %s <real> <imag>\n", argv[0]);
48               exit(EXIT_FAILURE);
49           }
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51           z = atof(argv[1]) + atof(argv[2]) * I;
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53           c = cacosh(z);
54           printf("cacosh() = %6.3f %6.3f*i\n", creal(c), cimag(c));
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56           f = 2 * clog(csqrt((z + 1)/2) + csqrt((z - 1)/2));
57           printf("formula  = %6.3f %6.3f*i\n", creal(f2), cimag(f2));
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59           exit(EXIT_SUCCESS);
60       }
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COLOPHON

66       This page is part of release 3.53 of the Linux  man-pages  project.   A
67       description  of  the project, and information about reporting bugs, can
68       be found at http://www.kernel.org/doc/man-pages/.
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72                                  2011-09-15                         CACOSH(3)