cacos(), cacosf(), cacosl()

Compute the 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 );

Arguments:

z
The value that you want to get the complex arc cosine of.

Library:

libm

Use the -l m option to qcc to link against this library.

Description:

These functions compute the complex arc cosine of z, with branch cuts outside the interval [−1, +1] along the real axis.

Returns:

The complex arc cosine of z, in the range [0; ) along the real axis and in the range [−iπ; iπ] along the imaginary axis.

If z is: These functions return:
±0+0i π/2-0i
±0+NaNi π/2+NaNi
x+i (for any finite x) π/2-i
x+NaNi (for any nonzero finite x) NaN+NaNi and FE_INVALID may be raised.
-+yi (for any positive finite y) π-i
-+yi (for any positive finite y) +0-i
-+i 3π/4-i
++i π/4-i
±+NaNi NaN±i (the sign of the imaginary part is unspecified)
NaN+yi (for any finite y) NaN+NaNi and FE_INVALID may be raised
NaN+i NaN-i
NaN+NaNi NaN+NaNi

Classification:

ANSI, POSIX 1003.1

Safety:  
Cancellation point No
Interrupt handler No
Signal handler No
Thread Yes