\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\begin{array}{l}
\mathbf{if}\;x \le -1.2887874422510308 \cdot 10^{-5}:\\
\;\;\;\;\sqrt{\frac{\sqrt{e^{2 \cdot x}} + \sqrt{1}}{1}} \cdot \sqrt{\frac{{\left(e^{2}\right)}^{\left(\frac{1}{2} \cdot x\right)} - \sqrt{1}}{e^{x} - 1}}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{x \cdot \left(1 + 0.5 \cdot x\right) + 2}\\
\end{array}double f(double x) {
double r11562 = 2.0;
double r11563 = x;
double r11564 = r11562 * r11563;
double r11565 = exp(r11564);
double r11566 = 1.0;
double r11567 = r11565 - r11566;
double r11568 = exp(r11563);
double r11569 = r11568 - r11566;
double r11570 = r11567 / r11569;
double r11571 = sqrt(r11570);
return r11571;
}
double f(double x) {
double r11572 = x;
double r11573 = -1.2887874422510308e-05;
bool r11574 = r11572 <= r11573;
double r11575 = 2.0;
double r11576 = r11575 * r11572;
double r11577 = exp(r11576);
double r11578 = sqrt(r11577);
double r11579 = 1.0;
double r11580 = sqrt(r11579);
double r11581 = r11578 + r11580;
double r11582 = 1.0;
double r11583 = r11581 / r11582;
double r11584 = sqrt(r11583);
double r11585 = exp(r11575);
double r11586 = 0.5;
double r11587 = r11586 * r11572;
double r11588 = pow(r11585, r11587);
double r11589 = r11588 - r11580;
double r11590 = exp(r11572);
double r11591 = r11590 - r11579;
double r11592 = r11589 / r11591;
double r11593 = sqrt(r11592);
double r11594 = r11584 * r11593;
double r11595 = 0.5;
double r11596 = r11595 * r11572;
double r11597 = r11579 + r11596;
double r11598 = r11572 * r11597;
double r11599 = r11598 + r11575;
double r11600 = sqrt(r11599);
double r11601 = r11574 ? r11594 : r11600;
return r11601;
}



Bits error versus x
Results
if x < -1.2887874422510308e-05Initial program 0.1
rmApplied *-un-lft-identity0.1
Applied add-sqr-sqrt0.1
Applied add-sqr-sqrt0.1
Applied difference-of-squares0.0
Applied times-frac0.0
Applied sqrt-prod0.0
rmApplied add-log-exp0.0
Applied exp-to-pow0.0
Applied sqrt-pow10.0
Simplified0.0
if -1.2887874422510308e-05 < x Initial program 34.6
Taylor expanded around 0 6.7
Simplified6.7
Final simplification0.9
herbie shell --seed 2020047
(FPCore (x)
:name "sqrtexp (problem 3.4.4)"
:precision binary64
(sqrt (/ (- (exp (* 2 x)) 1) (- (exp x) 1))))