CACOS(3) BSD Library Functions Manual CACOS(3)

NAME
     ccaaccooss - complex inverse cosine function

SYNOPSIS
     double complex
     ccaaccooss(double complex z);

     long double complex
     ccaaccoossll(long double complex z);

     float complex
     ccaaccoossff(float complex z);

DESCRIPTION
     ccaaccooss(z) computes the inverse cosine of the complex floating-point number
     z, with branch cuts outside the interval [-1,1] along the real axis.

     ccaaccooss() returns values in a strip of the complex plane with unbounded
     imaginary part, and real part in the interval [0, Pi].

     For all complex floating point numbers z, cacos(conj(z)) =
     conj(cacos(z)).

SSPPEECCIIAALL VVAALLUUEESS
     The conjugate symmetry of cacos() is used to abbreviate the specification
     of special values.

     ccaaccooss(+-0 + 0i) returns Pi/2 - 0i.

     ccaaccooss(+-0 + NaN i) returns Pi/2 + NaN i.

     ccaaccooss(x + inf i) returns Pi/2 - inf i, for finite x.

     ccaaccooss(x + NaN i) returns NaN + NaN i, for finite nonzero x.

     ccaaccooss(-inf + yi) returns Pi - inf i, for finite positive-signed y.

     ccaaccooss(inf + yi) returns 0 - inf i, for finite positive-signed y.

     ccaaccooss(-inf + inf i) returns 3Pi/4 - inf i.

     ccaaccooss(inf + inf i) returns Pi/4 - inf i.

     ccaaccooss(+-inf + NaN i) returns NaN + inf i.

     ccaaccooss(NaN + yi) returns NaN + NaN i, for finite y.

     ccaaccooss(NaN + inf i) returns NaN - inf i.

     ccaaccooss(NaN + NaN i) returns NaN + NaN i.

NNOOTTEESS
SEE ALSO
     complex(3)

STANDARDS     The ccaaccooss() function conforms to ISO/IEC 9899:1999(E).

4th Berkeley Distribution      November 9, 2006      4th Berkeley Distribution