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   cacos    ( 3 )

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Имя (Name)

cacos, cacosf, cacosl - complex arc cosine

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Синопсис (Synopsis)

#include <complex.h>

double complex cacos(double complex z); float complex cacosf(float complex z); long double complex cacosl(long double complex z);

Link with -lm.

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Описание (Description)

These functions calculate the complex arc cosine of z. If y = cacos(z), then z = ccos(y). The real part of y is chosen in the interval [0,pi].

One has:

cacos(z) = -i * clog(z + i * csqrt(1 - z * z))

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Версии (Versions)

These functions first appeared in glibc in version 2.1.

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Атрибуты (Attributes)

For an explanation of the terms used in this section, see attributes(7).

┌──────────────────────────────────────┬───────────────┬─────────┐ │Interface │ Attribute │ Value │ ├──────────────────────────────────────┼───────────────┼─────────┤ │cacos(), cacosf(), cacosl() │ Thread safety │ MT-Safe │ └──────────────────────────────────────┴───────────────┴─────────┘

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Стандарты (Conforming to)

C99, POSIX.1-2001, POSIX.1-2008.

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Примеры (Examples)

/* 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;
           double complex i = I;

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

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

           c = cacos(z);

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

           f = -i * clog(z + i * csqrt(1 - z * z));

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

           exit(EXIT_SUCCESS);
       }

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Смотри также (See also)

ccos(3), clog(3), complex(7)

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