\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 r1331492 = 2.0;
double r1331493 = x;
double r1331494 = r1331492 * r1331493;
double r1331495 = exp(r1331494);
double r1331496 = 1.0;
double r1331497 = r1331495 - r1331496;
double r1331498 = exp(r1331493);
double r1331499 = r1331498 - r1331496;
double r1331500 = r1331497 / r1331499;
double r1331501 = sqrt(r1331500);
return r1331501;
}
double f(double x) {
double r1331502 = x;
double r1331503 = -9.471958066473225e-06;
bool r1331504 = r1331502 <= r1331503;
double r1331505 = 1.0;
double r1331506 = sqrt(r1331505);
double r1331507 = 2.0;
double r1331508 = r1331507 * r1331502;
double r1331509 = exp(r1331508);
double r1331510 = sqrt(r1331509);
double r1331511 = r1331506 + r1331510;
double r1331512 = sqrt(r1331511);
double r1331513 = r1331512 * r1331512;
double r1331514 = exp(r1331502);
double r1331515 = r1331514 - r1331505;
double r1331516 = r1331510 - r1331506;
double r1331517 = r1331515 / r1331516;
double r1331518 = r1331513 / r1331517;
double r1331519 = sqrt(r1331518);
double r1331520 = 0.5;
double r1331521 = r1331502 * r1331520;
double r1331522 = r1331505 + r1331521;
double r1331523 = r1331502 * r1331522;
double r1331524 = r1331507 + r1331523;
double r1331525 = sqrt(r1331524);
double r1331526 = r1331504 ? r1331519 : r1331525;
return r1331526;
}



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))))