Average Error: 37.1 → 13.4
Time: 43.6s
Precision: 64
Internal Precision: 2368
\[\tan \left(x + \varepsilon\right) - \tan x\]
\[\begin{array}{l} \mathbf{if}\;\varepsilon \le -4.2459051660554507 \cdot 10^{-35} \lor \neg \left(\varepsilon \le 2.083346019454022 \cdot 10^{-42}\right):\\ \;\;\;\;\frac{\frac{\tan \varepsilon + \tan x}{1 - \tan \varepsilon \cdot \tan x} \cdot \frac{\tan \varepsilon + \tan x}{1 - \tan \varepsilon \cdot \tan x} - \tan x \cdot \tan x}{\frac{\tan \varepsilon + \tan x}{1 - \tan \varepsilon \cdot \tan x} + \tan x}\\ \mathbf{else}:\\ \;\;\;\;\left(\varepsilon \cdot \varepsilon\right) \cdot \left(\varepsilon \cdot \frac{1}{3} + x\right) + \varepsilon\\ \end{array}\]

Error

Bits error versus x

Bits error versus eps

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Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original37.1
Target15.7
Herbie13.4
\[\frac{\sin \varepsilon}{\cos x \cdot \cos \left(x + \varepsilon\right)}\]

Derivation

  1. Split input into 2 regimes
  2. if eps < -4.2459051660554507e-35 or 2.083346019454022e-42 < eps

    1. Initial program 30.8

      \[\tan \left(x + \varepsilon\right) - \tan x\]
    2. Initial simplification30.8

      \[\leadsto \tan \left(\varepsilon + x\right) - \tan x\]
    3. Using strategy rm
    4. Applied tan-sum2.8

      \[\leadsto \color{blue}{\frac{\tan \varepsilon + \tan x}{1 - \tan \varepsilon \cdot \tan x}} - \tan x\]
    5. Using strategy rm
    6. Applied flip--3.0

      \[\leadsto \color{blue}{\frac{\frac{\tan \varepsilon + \tan x}{1 - \tan \varepsilon \cdot \tan x} \cdot \frac{\tan \varepsilon + \tan x}{1 - \tan \varepsilon \cdot \tan x} - \tan x \cdot \tan x}{\frac{\tan \varepsilon + \tan x}{1 - \tan \varepsilon \cdot \tan x} + \tan x}}\]

    if -4.2459051660554507e-35 < eps < 2.083346019454022e-42

    1. Initial program 45.4

      \[\tan \left(x + \varepsilon\right) - \tan x\]
    2. Initial simplification45.4

      \[\leadsto \tan \left(\varepsilon + x\right) - \tan x\]
    3. Taylor expanded around 0 27.2

      \[\leadsto \color{blue}{x \cdot {\varepsilon}^{2} + \left(\frac{1}{3} \cdot {\varepsilon}^{3} + \varepsilon\right)}\]
    4. Simplified27.2

      \[\leadsto \color{blue}{\varepsilon + \left(\varepsilon \cdot \varepsilon\right) \cdot \left(x + \frac{1}{3} \cdot \varepsilon\right)}\]
  3. Recombined 2 regimes into one program.
  4. Final simplification13.4

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \le -4.2459051660554507 \cdot 10^{-35} \lor \neg \left(\varepsilon \le 2.083346019454022 \cdot 10^{-42}\right):\\ \;\;\;\;\frac{\frac{\tan \varepsilon + \tan x}{1 - \tan \varepsilon \cdot \tan x} \cdot \frac{\tan \varepsilon + \tan x}{1 - \tan \varepsilon \cdot \tan x} - \tan x \cdot \tan x}{\frac{\tan \varepsilon + \tan x}{1 - \tan \varepsilon \cdot \tan x} + \tan x}\\ \mathbf{else}:\\ \;\;\;\;\left(\varepsilon \cdot \varepsilon\right) \cdot \left(\varepsilon \cdot \frac{1}{3} + x\right) + \varepsilon\\ \end{array}\]

Runtime

Time bar (total: 43.6s)Debug logProfile

herbie shell --seed 2018254 
(FPCore (x eps)
  :name "2tan (problem 3.3.2)"

  :herbie-target
  (/ (sin eps) (* (cos x) (cos (+ x eps))))

  (- (tan (+ x eps)) (tan x)))