/* @(#)sinh.c 4.1 12/25/82 */ /* sinh(arg) returns the hyperbolic sine of its floating- point argument. The exponential function is called for arguments greater in magnitude than 0.5. A series is used for arguments smaller in magnitude than 0.5. The coefficients are #2029 from Hart & Cheney. (20.36D) cosh(arg) is computed from the exponential function for all arguments. */ double exp(); static double p0 = -0.6307673640497716991184787251e+6; static double p1 = -0.8991272022039509355398013511e+5; static double p2 = -0.2894211355989563807284660366e+4; static double p3 = -0.2630563213397497062819489e+2; static double q0 = -0.6307673640497716991212077277e+6; static double q1 = 0.1521517378790019070696485176e+5; static double q2 = -0.173678953558233699533450911e+3; double sinh(arg) double arg; { double temp, argsq; register sign; sign = 1; if(arg < 0) { arg = - arg; sign = -1; } if(arg > 21.) { temp = exp(arg)/2; if (sign>0) return(temp); else return(-temp); } if(arg > 0.5) { return(sign*(exp(arg) - exp(-arg))/2); } argsq = arg*arg; temp = (((p3*argsq+p2)*argsq+p1)*argsq+p0)*arg; temp /= (((argsq+q2)*argsq+q1)*argsq+q0); return(sign*temp); } double cosh(arg) double arg; { if(arg < 0) arg = - arg; if(arg > 21.) { return(exp(arg)/2); } return((exp(arg) + exp(-arg))/2); }