table of contents
cacos(3) | Library Functions Manual | cacos(3) |
NAME¶
cacos, cacosf, cacosl - complex arc cosine
LIBRARY¶
Math library (libm, -lm)
SYNOPSIS¶
#include <complex.h>
double complex cacos(double complex z); float complex cacosf(float complex z); long double complex cacosl(long double complex z);
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 were added in glibc 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 |
STANDARDS¶
C99, POSIX.1-2001, POSIX.1-2008.
EXAMPLES¶
/* Link with "-lm" */ #include <complex.h> #include <stdio.h> #include <stdlib.h> #include <unistd.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¶
2022-12-15 | Linux man-pages 6.03 |