\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\begin{array}{l}
\mathbf{if}\;x \le -1.9528378137991099 \cdot 10^{-15}:\\
\;\;\;\;\sqrt{\frac{\left(e^{x} + 1\right) \cdot \left(e^{2 \cdot x} - 1\right)}{e^{2 \cdot x} - 1}}\\
\mathbf{else}:\\
\;\;\;\;0.5 \cdot \frac{x}{\sqrt{2}} + \left(\sqrt{2} + \frac{{x}^{2}}{\sqrt{2}} \cdot \left(0.25 - \frac{0.125}{2}\right)\right)\\
\end{array}double f(double x) {
double r19359 = 2.0;
double r19360 = x;
double r19361 = r19359 * r19360;
double r19362 = exp(r19361);
double r19363 = 1.0;
double r19364 = r19362 - r19363;
double r19365 = exp(r19360);
double r19366 = r19365 - r19363;
double r19367 = r19364 / r19366;
double r19368 = sqrt(r19367);
return r19368;
}
double f(double x) {
double r19369 = x;
double r19370 = -1.95283781379911e-15;
bool r19371 = r19369 <= r19370;
double r19372 = exp(r19369);
double r19373 = 1.0;
double r19374 = r19372 + r19373;
double r19375 = 2.0;
double r19376 = r19375 * r19369;
double r19377 = exp(r19376);
double r19378 = r19377 - r19373;
double r19379 = r19374 * r19378;
double r19380 = 2.0;
double r19381 = r19380 * r19369;
double r19382 = exp(r19381);
double r19383 = r19382 - r19373;
double r19384 = r19379 / r19383;
double r19385 = sqrt(r19384);
double r19386 = 0.5;
double r19387 = sqrt(r19375);
double r19388 = r19369 / r19387;
double r19389 = r19386 * r19388;
double r19390 = pow(r19369, r19380);
double r19391 = r19390 / r19387;
double r19392 = 0.25;
double r19393 = 0.125;
double r19394 = r19393 / r19375;
double r19395 = r19392 - r19394;
double r19396 = r19391 * r19395;
double r19397 = r19387 + r19396;
double r19398 = r19389 + r19397;
double r19399 = r19371 ? r19385 : r19398;
return r19399;
}



Bits error versus x
Results
if x < -1.95283781379911e-15Initial program 0.7
rmApplied flip--0.5
Simplified0.0
Taylor expanded around inf 0.0
if -1.95283781379911e-15 < x Initial program 37.6
Taylor expanded around 0 8.2
Simplified8.2
Final simplification0.8
herbie shell --seed 2020081 +o rules:numerics
(FPCore (x)
:name "sqrtexp (problem 3.4.4)"
:precision binary64
(sqrt (/ (- (exp (* 2 x)) 1) (- (exp x) 1))))