\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\begin{array}{l}
\mathbf{if}\;x \le -2.5679454952614643 \cdot 10^{-15}:\\
\;\;\;\;\sqrt{\frac{\sqrt[3]{{\left(e^{2 \cdot x} - 1\right)}^{3}}}{e^{x + x} - 1 \cdot 1}} \cdot \sqrt{e^{x} + 1}\\
\mathbf{else}:\\
\;\;\;\;\left(\sqrt{2} + 0.5 \cdot \frac{x}{\sqrt{2}}\right) + \frac{{x}^{2}}{\sqrt{2}} \cdot \left(0.25 - \frac{0.125}{2}\right)\\
\end{array}double f(double x) {
double r18168 = 2.0;
double r18169 = x;
double r18170 = r18168 * r18169;
double r18171 = exp(r18170);
double r18172 = 1.0;
double r18173 = r18171 - r18172;
double r18174 = exp(r18169);
double r18175 = r18174 - r18172;
double r18176 = r18173 / r18175;
double r18177 = sqrt(r18176);
return r18177;
}
double f(double x) {
double r18178 = x;
double r18179 = -2.5679454952614643e-15;
bool r18180 = r18178 <= r18179;
double r18181 = 2.0;
double r18182 = r18181 * r18178;
double r18183 = exp(r18182);
double r18184 = 1.0;
double r18185 = r18183 - r18184;
double r18186 = 3.0;
double r18187 = pow(r18185, r18186);
double r18188 = cbrt(r18187);
double r18189 = r18178 + r18178;
double r18190 = exp(r18189);
double r18191 = r18184 * r18184;
double r18192 = r18190 - r18191;
double r18193 = r18188 / r18192;
double r18194 = sqrt(r18193);
double r18195 = exp(r18178);
double r18196 = r18195 + r18184;
double r18197 = sqrt(r18196);
double r18198 = r18194 * r18197;
double r18199 = sqrt(r18181);
double r18200 = 0.5;
double r18201 = r18178 / r18199;
double r18202 = r18200 * r18201;
double r18203 = r18199 + r18202;
double r18204 = 2.0;
double r18205 = pow(r18178, r18204);
double r18206 = r18205 / r18199;
double r18207 = 0.25;
double r18208 = 0.125;
double r18209 = r18208 / r18181;
double r18210 = r18207 - r18209;
double r18211 = r18206 * r18210;
double r18212 = r18203 + r18211;
double r18213 = r18180 ? r18198 : r18212;
return r18213;
}



Bits error versus x
Results
if x < -2.5679454952614643e-15Initial program 0.7
rmApplied flip--0.4
Applied associate-/r/0.4
Applied sqrt-prod0.4
Simplified0.0
rmApplied add-cbrt-cube0.0
Simplified0.0
if -2.5679454952614643e-15 < x Initial program 38.5
Taylor expanded around 0 7.4
Simplified7.4
Final simplification0.7
herbie shell --seed 2020045
(FPCore (x)
:name "sqrtexp (problem 3.4.4)"
:precision binary64
(sqrt (/ (- (exp (* 2 x)) 1) (- (exp x) 1))))