cacos (3)

NAME

cacos, cacosf, cacosl - complex arc cosine

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.

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))

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).
Interface Attribute Value
cacos (), cacosf (), cacosl () Thread safety MT-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; 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); }

SEE ALSO

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

Information

Source
Linux kernel
OS/version
Source updated
April 19, 2015
Page created
February 9, 2018
Page generated
December 2, 2018