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   cacos    ( 3 )

комплексный арккосинус (complex arc cosine)

Имя (Name)

cacos, cacosf, cacosl - complex arc cosine


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.


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))


Версии (Versions)

These functions first appeared in glibc in version 2.1.


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 │ └──────────────────────────────────────┴───────────────┴─────────┘


Стандарты (Conforming to)

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


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); }


Смотри также (See also)

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