Average Error: 2.2 → 0.2
Time: 2.0m
Precision: 64
Internal Precision: 128
\[\frac{a \cdot {k}^{m}}{\left(1 + 10 \cdot k\right) + k \cdot k}\]
\[\begin{array}{l} \mathbf{if}\;k \le 8.236251385880573 \cdot 10^{+87}:\\ \;\;\;\;\frac{a}{\frac{(k \cdot \left(k + 10\right) + 1)_*}{{k}^{m}}}\\ \mathbf{else}:\\ \;\;\;\;(\left(\frac{\frac{e^{\log k \cdot m}}{\frac{k}{a} \cdot k}}{k}\right) \cdot -10 + \left((99 \cdot \left(\frac{e^{\log k \cdot m}}{\frac{{k}^{4}}{a}}\right) + \left(\frac{e^{\log k \cdot m}}{\frac{k}{a} \cdot k}\right))_*\right))_*\\ \end{array}\]

Error

Bits error versus a

Bits error versus k

Bits error versus m

Derivation

  1. Split input into 2 regimes
  2. if k < 8.236251385880573e+87

    1. Initial program 0.1

      \[\frac{a \cdot {k}^{m}}{\left(1 + 10 \cdot k\right) + k \cdot k}\]
    2. Simplified0.0

      \[\leadsto \color{blue}{\frac{a}{\frac{(k \cdot \left(k + 10\right) + 1)_*}{{k}^{m}}}}\]

    if 8.236251385880573e+87 < k

    1. Initial program 7.8

      \[\frac{a \cdot {k}^{m}}{\left(1 + 10 \cdot k\right) + k \cdot k}\]
    2. Simplified7.8

      \[\leadsto \color{blue}{\frac{a}{\frac{(k \cdot \left(k + 10\right) + 1)_*}{{k}^{m}}}}\]
    3. Taylor expanded around inf 7.8

      \[\leadsto \color{blue}{\left(99 \cdot \frac{e^{-1 \cdot \left(\log \left(\frac{1}{k}\right) \cdot m\right)} \cdot a}{{k}^{4}} + \frac{e^{-1 \cdot \left(\log \left(\frac{1}{k}\right) \cdot m\right)} \cdot a}{{k}^{2}}\right) - 10 \cdot \frac{e^{-1 \cdot \left(\log \left(\frac{1}{k}\right) \cdot m\right)} \cdot a}{{k}^{3}}}\]
    4. Simplified0.6

      \[\leadsto \color{blue}{(\left(\frac{\frac{e^{\log k \cdot m}}{\frac{k}{a} \cdot k}}{k}\right) \cdot -10 + \left((99 \cdot \left(\frac{e^{\log k \cdot m}}{\frac{{k}^{4}}{a}}\right) + \left(\frac{e^{\log k \cdot m}}{\frac{k}{a} \cdot k}\right))_*\right))_*}\]
  3. Recombined 2 regimes into one program.
  4. Final simplification0.2

    \[\leadsto \begin{array}{l} \mathbf{if}\;k \le 8.236251385880573 \cdot 10^{+87}:\\ \;\;\;\;\frac{a}{\frac{(k \cdot \left(k + 10\right) + 1)_*}{{k}^{m}}}\\ \mathbf{else}:\\ \;\;\;\;(\left(\frac{\frac{e^{\log k \cdot m}}{\frac{k}{a} \cdot k}}{k}\right) \cdot -10 + \left((99 \cdot \left(\frac{e^{\log k \cdot m}}{\frac{{k}^{4}}{a}}\right) + \left(\frac{e^{\log k \cdot m}}{\frac{k}{a} \cdot k}\right))_*\right))_*\\ \end{array}\]

Reproduce

herbie shell --seed 2019050 +o rules:numerics
(FPCore (a k m)
  :name "Falkner and Boettcher, Appendix A"
  (/ (* a (pow k m)) (+ (+ 1 (* 10 k)) (* k k))))