\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\begin{array}{l}
\mathbf{if}\;x \le -9.47195806647322485446235246220325620925 \cdot 10^{-6}:\\
\;\;\;\;\sqrt{\frac{\sqrt{\sqrt{1} + \sqrt{e^{2 \cdot x}}} \cdot \sqrt{\sqrt{1} + \sqrt{e^{2 \cdot x}}}}{\frac{e^{x} - 1}{\sqrt{e^{2 \cdot x}} - \sqrt{1}}}}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{2 + x \cdot \left(1 + x \cdot 0.5\right)}\\
\end{array}double f(double x) {
double r1207455 = 2.0;
double r1207456 = x;
double r1207457 = r1207455 * r1207456;
double r1207458 = exp(r1207457);
double r1207459 = 1.0;
double r1207460 = r1207458 - r1207459;
double r1207461 = exp(r1207456);
double r1207462 = r1207461 - r1207459;
double r1207463 = r1207460 / r1207462;
double r1207464 = sqrt(r1207463);
return r1207464;
}
double f(double x) {
double r1207465 = x;
double r1207466 = -9.471958066473225e-06;
bool r1207467 = r1207465 <= r1207466;
double r1207468 = 1.0;
double r1207469 = sqrt(r1207468);
double r1207470 = 2.0;
double r1207471 = r1207470 * r1207465;
double r1207472 = exp(r1207471);
double r1207473 = sqrt(r1207472);
double r1207474 = r1207469 + r1207473;
double r1207475 = sqrt(r1207474);
double r1207476 = r1207475 * r1207475;
double r1207477 = exp(r1207465);
double r1207478 = r1207477 - r1207468;
double r1207479 = r1207473 - r1207469;
double r1207480 = r1207478 / r1207479;
double r1207481 = r1207476 / r1207480;
double r1207482 = sqrt(r1207481);
double r1207483 = 0.5;
double r1207484 = r1207465 * r1207483;
double r1207485 = r1207468 + r1207484;
double r1207486 = r1207465 * r1207485;
double r1207487 = r1207470 + r1207486;
double r1207488 = sqrt(r1207487);
double r1207489 = r1207467 ? r1207482 : r1207488;
return r1207489;
}



Bits error versus x
Results
if x < -9.471958066473225e-06Initial program 0.1
rmApplied add-sqr-sqrt0.1
Applied add-sqr-sqrt0.1
Applied difference-of-squares0.0
Applied associate-/l*0.0
rmApplied add-sqr-sqrt0.0
if -9.471958066473225e-06 < x Initial program 34.5
Taylor expanded around 0 6.5
Simplified6.5
Final simplification0.8
herbie shell --seed 2019172
(FPCore (x)
:name "sqrtexp (problem 3.4.4)"
(sqrt (/ (- (exp (* 2.0 x)) 1.0) (- (exp x) 1.0))))