\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 r68472 = 2.0;
double r68473 = x;
double r68474 = exp(r68473);
double r68475 = -r68473;
double r68476 = exp(r68475);
double r68477 = r68474 + r68476;
double r68478 = r68472 / r68477;
return r68478;
}
double f(double x) {
double r68479 = 2.0;
double r68480 = x;
double r68481 = exp(r68480);
double r68482 = -r68480;
double r68483 = exp(r68482);
double r68484 = r68481 + r68483;
double r68485 = r68479 / r68484;
double r68486 = sqrt(r68485);
double r68487 = sqrt(r68479);
double r68488 = sqrt(r68487);
double r68489 = r68486 * r68488;
double r68490 = r68487 / r68484;
double r68491 = sqrt(r68490);
double r68492 = r68489 * r68491;
return r68492;
}



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 +o rules:numerics
(FPCore (x)
:name "Hyperbolic secant"
:precision binary64
(/ 2 (+ (exp x) (exp (- x)))))