\frac{2}{e^{x} + e^{-x}}\left(\sqrt{\frac{2}{e^{-x} + e^{x}}} \cdot \sqrt{\sqrt{2}}\right) \cdot \sqrt{\frac{\sqrt{2}}{e^{x} + e^{-x}}}double f(double x) {
double r55991 = 2.0;
double r55992 = x;
double r55993 = exp(r55992);
double r55994 = -r55992;
double r55995 = exp(r55994);
double r55996 = r55993 + r55995;
double r55997 = r55991 / r55996;
return r55997;
}
double f(double x) {
double r55998 = 2.0;
double r55999 = x;
double r56000 = -r55999;
double r56001 = exp(r56000);
double r56002 = exp(r55999);
double r56003 = r56001 + r56002;
double r56004 = r55998 / r56003;
double r56005 = sqrt(r56004);
double r56006 = sqrt(r55998);
double r56007 = sqrt(r56006);
double r56008 = r56005 * r56007;
double r56009 = r56002 + r56001;
double r56010 = r56006 / r56009;
double r56011 = sqrt(r56010);
double r56012 = r56008 * r56011;
return r56012;
}



Bits error versus x
Results
Initial program 0.0
rmApplied add-sqr-sqrt0.0
rmApplied *-un-lft-identity0.0
Applied add-sqr-sqrt0.0
Applied times-frac0.0
Applied sqrt-prod0.0
Applied associate-*r*0.0
Simplified0.0
Final simplification0.0
herbie shell --seed 2019323
(FPCore (x)
:name "Hyperbolic secant"
:precision binary64
(/ 2 (+ (exp x) (exp (- x)))))