\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\begin{array}{l}
\mathbf{if}\;x \le -6.207265300769888841194911957148031651441 \cdot 10^{-12}:\\
\;\;\;\;\sqrt{\frac{\left|\sqrt[3]{e^{2 \cdot x}}\right| \cdot \sqrt{\sqrt[3]{e^{2 \cdot x}}} + \sqrt{1}}{\frac{e^{x} - 1}{{\left(e^{2}\right)}^{\left(\frac{x}{2}\right)} - \sqrt{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 r27180 = 2.0;
double r27181 = x;
double r27182 = r27180 * r27181;
double r27183 = exp(r27182);
double r27184 = 1.0;
double r27185 = r27183 - r27184;
double r27186 = exp(r27181);
double r27187 = r27186 - r27184;
double r27188 = r27185 / r27187;
double r27189 = sqrt(r27188);
return r27189;
}
double f(double x) {
double r27190 = x;
double r27191 = -6.207265300769889e-12;
bool r27192 = r27190 <= r27191;
double r27193 = 2.0;
double r27194 = r27193 * r27190;
double r27195 = exp(r27194);
double r27196 = cbrt(r27195);
double r27197 = fabs(r27196);
double r27198 = sqrt(r27196);
double r27199 = r27197 * r27198;
double r27200 = 1.0;
double r27201 = sqrt(r27200);
double r27202 = r27199 + r27201;
double r27203 = exp(r27190);
double r27204 = r27203 - r27200;
double r27205 = exp(r27193);
double r27206 = 2.0;
double r27207 = r27190 / r27206;
double r27208 = pow(r27205, r27207);
double r27209 = r27208 - r27201;
double r27210 = r27204 / r27209;
double r27211 = r27202 / r27210;
double r27212 = sqrt(r27211);
double r27213 = 0.5;
double r27214 = sqrt(r27193);
double r27215 = r27190 / r27214;
double r27216 = r27213 * r27215;
double r27217 = pow(r27190, r27206);
double r27218 = r27217 / r27214;
double r27219 = 0.25;
double r27220 = 0.125;
double r27221 = r27220 / r27193;
double r27222 = r27219 - r27221;
double r27223 = r27218 * r27222;
double r27224 = r27214 + r27223;
double r27225 = r27216 + r27224;
double r27226 = r27192 ? r27212 : r27225;
return r27226;
}



Bits error versus x
Results
if x < -6.207265300769889e-12Initial program 0.5
rmApplied add-sqr-sqrt0.5
Applied add-sqr-sqrt0.4
Applied difference-of-squares0.1
Applied associate-/l*0.1
rmApplied add-log-exp0.1
Applied exp-to-pow0.1
Applied sqrt-pow10.0
rmApplied add-cube-cbrt0.0
Applied sqrt-prod0.0
Simplified0.0
if -6.207265300769889e-12 < x Initial program 37.2
Taylor expanded around 0 7.4
Simplified7.4
Final simplification0.8
herbie shell --seed 2019308
(FPCore (x)
:name "sqrtexp (problem 3.4.4)"
:precision binary64
(sqrt (/ (- (exp (* 2 x)) 1) (- (exp x) 1))))