Average Error: 4.6 → 0.9
Time: 12.9s
Precision: 64
\[\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\]
\[\begin{array}{l} \mathbf{if}\;x \le -1.2887874422510308 \cdot 10^{-5}:\\ \;\;\;\;\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x + x} - 1 \cdot 1}} \cdot \sqrt{e^{x} + 1}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{2 + x \cdot \left(1 + 0.5 \cdot x\right)}\\ \end{array}\]
\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}
\begin{array}{l}
\mathbf{if}\;x \le -1.2887874422510308 \cdot 10^{-5}:\\
\;\;\;\;\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x + x} - 1 \cdot 1}} \cdot \sqrt{e^{x} + 1}\\

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

\end{array}
double f(double x) {
        double r10912 = 2.0;
        double r10913 = x;
        double r10914 = r10912 * r10913;
        double r10915 = exp(r10914);
        double r10916 = 1.0;
        double r10917 = r10915 - r10916;
        double r10918 = exp(r10913);
        double r10919 = r10918 - r10916;
        double r10920 = r10917 / r10919;
        double r10921 = sqrt(r10920);
        return r10921;
}

double f(double x) {
        double r10922 = x;
        double r10923 = -1.2887874422510308e-05;
        bool r10924 = r10922 <= r10923;
        double r10925 = 2.0;
        double r10926 = r10925 * r10922;
        double r10927 = exp(r10926);
        double r10928 = 1.0;
        double r10929 = r10927 - r10928;
        double r10930 = r10922 + r10922;
        double r10931 = exp(r10930);
        double r10932 = r10928 * r10928;
        double r10933 = r10931 - r10932;
        double r10934 = r10929 / r10933;
        double r10935 = sqrt(r10934);
        double r10936 = exp(r10922);
        double r10937 = r10936 + r10928;
        double r10938 = sqrt(r10937);
        double r10939 = r10935 * r10938;
        double r10940 = 0.5;
        double r10941 = r10940 * r10922;
        double r10942 = r10928 + r10941;
        double r10943 = r10922 * r10942;
        double r10944 = r10925 + r10943;
        double r10945 = sqrt(r10944);
        double r10946 = r10924 ? r10939 : r10945;
        return r10946;
}

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 < -1.2887874422510308e-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. Applied sqrt-prod0.1

      \[\leadsto \color{blue}{\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} \cdot e^{x} - 1 \cdot 1}} \cdot \sqrt{e^{x} + 1}}\]
    6. Simplified0.0

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

    if -1.2887874422510308e-05 < x

    1. Initial program 34.6

      \[\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\]
    2. Taylor expanded around 0 6.7

      \[\leadsto \sqrt{\color{blue}{0.5 \cdot {x}^{2} + \left(1 \cdot x + 2\right)}}\]
    3. Simplified6.7

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \le -1.2887874422510308 \cdot 10^{-5}:\\ \;\;\;\;\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x + x} - 1 \cdot 1}} \cdot \sqrt{e^{x} + 1}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{2 + x \cdot \left(1 + 0.5 \cdot x\right)}\\ \end{array}\]

Reproduce

herbie shell --seed 2020047 
(FPCore (x)
  :name "sqrtexp (problem 3.4.4)"
  :precision binary64
  (sqrt (/ (- (exp (* 2 x)) 1) (- (exp x) 1))))