Average Error: 4.7 → 0.9
Time: 24.7s
Precision: 64
\[\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\]
\[\begin{array}{l} \mathbf{if}\;x \le -1.308379721855004695332726910583787116593 \cdot 10^{-5}:\\ \;\;\;\;\sqrt{\left(\left(e^{2 \cdot x} - 1\right) \cdot \frac{1}{e^{x + x} - 1 \cdot 1}\right) \cdot \left(e^{x} + 1\right)}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{2 + x \cdot \left(1 + 0.5 \cdot x\right)}\\ \end{array}\]
\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}
\begin{array}{l}
\mathbf{if}\;x \le -1.308379721855004695332726910583787116593 \cdot 10^{-5}:\\
\;\;\;\;\sqrt{\left(\left(e^{2 \cdot x} - 1\right) \cdot \frac{1}{e^{x + x} - 1 \cdot 1}\right) \cdot \left(e^{x} + 1\right)}\\

\mathbf{else}:\\
\;\;\;\;\sqrt{2 + x \cdot \left(1 + 0.5 \cdot x\right)}\\

\end{array}
double f(double x) {
        double r24889 = 2.0;
        double r24890 = x;
        double r24891 = r24889 * r24890;
        double r24892 = exp(r24891);
        double r24893 = 1.0;
        double r24894 = r24892 - r24893;
        double r24895 = exp(r24890);
        double r24896 = r24895 - r24893;
        double r24897 = r24894 / r24896;
        double r24898 = sqrt(r24897);
        return r24898;
}

double f(double x) {
        double r24899 = x;
        double r24900 = -1.3083797218550047e-05;
        bool r24901 = r24899 <= r24900;
        double r24902 = 2.0;
        double r24903 = r24902 * r24899;
        double r24904 = exp(r24903);
        double r24905 = 1.0;
        double r24906 = r24904 - r24905;
        double r24907 = 1.0;
        double r24908 = r24899 + r24899;
        double r24909 = exp(r24908);
        double r24910 = r24905 * r24905;
        double r24911 = r24909 - r24910;
        double r24912 = r24907 / r24911;
        double r24913 = r24906 * r24912;
        double r24914 = exp(r24899);
        double r24915 = r24914 + r24905;
        double r24916 = r24913 * r24915;
        double r24917 = sqrt(r24916);
        double r24918 = 0.5;
        double r24919 = r24918 * r24899;
        double r24920 = r24905 + r24919;
        double r24921 = r24899 * r24920;
        double r24922 = r24902 + r24921;
        double r24923 = sqrt(r24922);
        double r24924 = r24901 ? r24917 : r24923;
        return r24924;
}

Error

Bits error versus x

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Split input into 2 regimes
  2. if x < -1.3083797218550047e-05

    1. Initial program 0.1

      \[\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\]
    2. Using strategy rm
    3. Applied flip--0.1

      \[\leadsto \sqrt{\frac{e^{2 \cdot x} - 1}{\color{blue}{\frac{e^{x} \cdot e^{x} - 1 \cdot 1}{e^{x} + 1}}}}\]
    4. Applied associate-/r/0.1

      \[\leadsto \sqrt{\color{blue}{\frac{e^{2 \cdot x} - 1}{e^{x} \cdot e^{x} - 1 \cdot 1} \cdot \left(e^{x} + 1\right)}}\]
    5. Simplified0.0

      \[\leadsto \sqrt{\color{blue}{\frac{e^{2 \cdot x} - 1}{e^{x + x} - 1 \cdot 1}} \cdot \left(e^{x} + 1\right)}\]
    6. Using strategy rm
    7. Applied div-inv0.0

      \[\leadsto \sqrt{\color{blue}{\left(\left(e^{2 \cdot x} - 1\right) \cdot \frac{1}{e^{x + x} - 1 \cdot 1}\right)} \cdot \left(e^{x} + 1\right)}\]

    if -1.3083797218550047e-05 < x

    1. Initial program 34.5

      \[\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\]
    2. Taylor expanded around 0 6.4

      \[\leadsto \sqrt{\color{blue}{0.5 \cdot {x}^{2} + \left(1 \cdot x + 2\right)}}\]
    3. Simplified6.4

      \[\leadsto \sqrt{\color{blue}{2 + x \cdot \left(1 + 0.5 \cdot x\right)}}\]
  3. Recombined 2 regimes into one program.
  4. Final simplification0.9

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \le -1.308379721855004695332726910583787116593 \cdot 10^{-5}:\\ \;\;\;\;\sqrt{\left(\left(e^{2 \cdot x} - 1\right) \cdot \frac{1}{e^{x + x} - 1 \cdot 1}\right) \cdot \left(e^{x} + 1\right)}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{2 + x \cdot \left(1 + 0.5 \cdot x\right)}\\ \end{array}\]

Reproduce

herbie shell --seed 2019303 
(FPCore (x)
  :name "sqrtexp (problem 3.4.4)"
  :precision binary64
  (sqrt (/ (- (exp (* 2 x)) 1) (- (exp x) 1))))