4.3BSD - /usr/src/usr.lib/libom/tanh.c

   1: /*	@(#)tanh.c	4.1	12/25/82	*/
   2: 
   3: /*
   4: 	tanh(arg) computes the hyperbolic tangent of its floating
   5: 	point argument.
   6: 
   7: 	sinh and cosh are called except for large arguments, which
   8: 	would cause overflow improperly.
   9: */
  10: 
  11: double sinh(), cosh();
  12: 
  13: double
  14: tanh(arg)
  15: double arg;
  16: {
  17:     double sign;
  18: 
  19:     sign = 1.;
  20:     if(arg < 0.){
  21:         arg = -arg;
  22:         sign = -1.;
  23:     }
  24: 
  25:     if(arg > 21.)
  26:         return(sign);
  27: 
  28:     return(sign*sinh(arg)/cosh(arg));
  29: }

Defined functions