cacosh(3) BSD Library Functions Manual cacosh(3)
NAME
cacosh -- complex inverse hyperbolic cosine function
SYNOPSIS
double complex
cacosh(double complex z);
long double complex
cacoshl(long double complex z);
float complex
cacoshf(float complex z);
DESCRIPTION
cacosh(z) computes the inverse hyperbolic cosine of the complex floating-
point number z, with a branch cut on the interval [-inf, 1] along the
real axis.
cacosh() returns values in a half-strip of the complex plane with posi-
tive real part and imaginary part in the interval [-Pi, Pi].
For all complex floating point numbers z, cacosh(conj(z)) =
conj(cacosh(z)).
SPECIAL VALUES
The conjugate symmetry of cacosh() is used to abbreviate the specifica-
tion of special values.
cacosh(+-0 + 0i) returns 0 + Pi/2 i.
cacosh(x + inf i) returns inf + Pi/2 i, for finite x.
cacosh(x + NaN i) returns NaN + NaN i, for finite nonzero x.
cacosh(-inf + yi) returns inf + Pi i, for finite positive-signed y.
cacosh(inf + yi) returns inf + 0i, for finite positive-signed y.
cacosh(-inf + inf i) returns inf + 3Pi/4 i.
cacosh(inf + inf i) returns inf + Pi/4 i.
cacosh(+-inf + NaN i) returns inf + NaN i.
cacosh(NaN + yi) returns NaN + NaN i, for finite y.
cacosh(NaN + inf i) returns inf + NaN i.
cacosh(NaN + NaN i) returns NaN + NaN i.
NOTES
SEE ALSO
ccosh(3) complex(3)
STANDARDS
The cacosh() function conforms to ISO/IEC 9899:1999(E).
4th Berkeley Distribution December 11, 2006 4th Berkeley Distribution
Mac OS X 10.6 - Generated Thu Sep 17 20:18:41 CDT 2009