1 /*- 2 * Copyright (c) 1980 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.proprietary.c% 6 */ 7 8 #ifndef lint 9 static char sccsid[] = "@(#)c_cos.c 5.2 (Berkeley) 04/12/91"; 10 #endif /* not lint */ 11 12 #include "complex" 13 14 c_cos(r, z) 15 complex *r, *z; 16 { 17 double sin(), cos(), sinh(), cosh(); 18 19 r->real = cos(z->real) * cosh(z->imag); 20 r->imag = - sin(z->real) * sinh(z->imag); 21 } 22