.\" Copyright 2002 Walter Harms(walter.harms@informatik.uni-oldenburg.de)
+.\" and Copyright (C) 2011 Michael Kerrisk <mtk.manpages@gamil.com>
.\" Distributed under GPL
.\"
-.TH CACOSH 3 2008-08-11 "" "Linux Programmer's Manual"
+.TH CACOSH 3 2011-09-15 "" "Linux Programmer's Manual"
.SH NAME
cacosh, cacoshf, cacoshl \- complex arc hyperbolic cosine
.SH SYNOPSIS
One has:
.nf
- cacosh(z) = (0.5) * clog((1 + z) / (1 \- z))
+ cacosh(z) = 2 * clog(csqrt((z + 1) / 2) + csqrt((z \- 1) / 2))
.fi
.SH VERSIONS
These functions first appeared in glibc in version 2.1.
.SH "CONFORMING TO"
C99.
+.SH EXAMPLE
+.nf
+/* 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;
+
+ if (argc != 3) {
+ fprintf(stderr, "Usage: %s <real> <imag>\\n", argv[0]);
+ exit(EXIT_FAILURE);
+ }
+
+ z = atof(argv[1]) + atof(argv[2]) * I;
+
+ c = cacosh(z);
+ printf("cacosh() = %6.3f %6.3f*i\\n", creal(c), cimag(c));
+
+ f = 2 * clog(csqrt((z + 1)/2) + csqrt((z \- 1)/2));
+ printf("formula = %6.3f %6.3f*i\\n", creal(f2), cimag(f2));
+
+ exit(EXIT_SUCCESS);
+}
+.fi
.SH "SEE ALSO"
.BR acosh (3),
.BR cabs (3),
+.BR ccosh (3),
.BR cimag (3),
.BR complex (7)