Average Error: 4.7 → 0.8
Time: 23.9s
Precision: 64
\[\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\]
\[\begin{array}{l} \mathbf{if}\;x \le -4.54501292903996873 \cdot 10^{-10}:\\ \;\;\;\;\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x + x} - 1 \cdot 1}} \cdot \sqrt{e^{x} + 1}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{2 + x \cdot \left(0.5 \cdot x + 1\right)}\\ \end{array}\]
\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}
\begin{array}{l}
\mathbf{if}\;x \le -4.54501292903996873 \cdot 10^{-10}:\\
\;\;\;\;\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(0.5 \cdot x + 1\right)}\\

\end{array}
double f(double x) {
        double r19587 = 2.0;
        double r19588 = x;
        double r19589 = r19587 * r19588;
        double r19590 = exp(r19589);
        double r19591 = 1.0;
        double r19592 = r19590 - r19591;
        double r19593 = exp(r19588);
        double r19594 = r19593 - r19591;
        double r19595 = r19592 / r19594;
        double r19596 = sqrt(r19595);
        return r19596;
}

double f(double x) {
        double r19597 = x;
        double r19598 = -4.5450129290399687e-10;
        bool r19599 = r19597 <= r19598;
        double r19600 = 2.0;
        double r19601 = r19600 * r19597;
        double r19602 = exp(r19601);
        double r19603 = 1.0;
        double r19604 = r19602 - r19603;
        double r19605 = r19597 + r19597;
        double r19606 = exp(r19605);
        double r19607 = r19603 * r19603;
        double r19608 = r19606 - r19607;
        double r19609 = r19604 / r19608;
        double r19610 = sqrt(r19609);
        double r19611 = exp(r19597);
        double r19612 = r19611 + r19603;
        double r19613 = sqrt(r19612);
        double r19614 = r19610 * r19613;
        double r19615 = 0.5;
        double r19616 = r19615 * r19597;
        double r19617 = r19616 + r19603;
        double r19618 = r19597 * r19617;
        double r19619 = r19600 + r19618;
        double r19620 = sqrt(r19619);
        double r19621 = r19599 ? r19614 : r19620;
        return r19621;
}

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 < -4.5450129290399687e-10

    1. Initial program 0.3

      \[\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\]
    2. Using strategy rm
    3. Applied flip--0.2

      \[\leadsto \sqrt{\frac{e^{2 \cdot x} - 1}{\color{blue}{\frac{e^{x} \cdot e^{x} - 1 \cdot 1}{e^{x} + 1}}}}\]
    4. Applied associate-/r/0.2

      \[\leadsto \sqrt{\color{blue}{\frac{e^{2 \cdot x} - 1}{e^{x} \cdot e^{x} - 1 \cdot 1} \cdot \left(e^{x} + 1\right)}}\]
    5. Applied sqrt-prod0.2

      \[\leadsto \color{blue}{\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} \cdot e^{x} - 1 \cdot 1}} \cdot \sqrt{e^{x} + 1}}\]
    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 -4.5450129290399687e-10 < x

    1. Initial program 38.3

      \[\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x} - 1}}\]
    2. Taylor expanded around 0 7.0

      \[\leadsto \sqrt{\color{blue}{0.5 \cdot {x}^{2} + \left(1 \cdot x + 2\right)}}\]
    3. Simplified7.0

      \[\leadsto \sqrt{\color{blue}{2 + x \cdot \left(0.5 \cdot x + 1\right)}}\]
  3. Recombined 2 regimes into one program.
  4. Final simplification0.8

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \le -4.54501292903996873 \cdot 10^{-10}:\\ \;\;\;\;\sqrt{\frac{e^{2 \cdot x} - 1}{e^{x + x} - 1 \cdot 1}} \cdot \sqrt{e^{x} + 1}\\ \mathbf{else}:\\ \;\;\;\;\sqrt{2 + x \cdot \left(0.5 \cdot x + 1\right)}\\ \end{array}\]

Reproduce

herbie shell --seed 2019199 
(FPCore (x)
  :name "sqrtexp (problem 3.4.4)"
  (sqrt (/ (- (exp (* 2.0 x)) 1.0) (- (exp x) 1.0))))