1 /* Return cosine of complex double value. 2 Copyright (C) 1997 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. 5 6 The GNU C Library is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Lesser General Public 8 License as published by the Free Software Foundation; either 9 version 2.1 of the License, or (at your option) any later version. 10 11 The GNU C Library is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 You should have received a copy of the GNU Lesser General Public 17 License along with the GNU C Library; if not, write to the Free 18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 19 02111-1307 USA. */ 20 21 #include <complex.h> 22 #include <math.h> 23 24 __complex__ double 25 __cacos (__complex__ double x) 26 { 27 __complex__ double y; 28 __complex__ double res; 29 30 y = __casin (x); 31 32 __real__ res = (double) M_PI_2 - __real__ y; 33 __imag__ res = -__imag__ y; 34 35 return res; 36 } 37 weak_alias (__cacos, cacos) 38 #ifdef NO_LONG_DOUBLE 39 strong_alias (__cacos, __cacosl) 40 weak_alias (__cacos, cacosl) 41 #endif 42