Average Error: 36.7 → 0.4
Time: 50.2s
Precision: 64
Internal Precision: 2368
\[\tan \left(x + \varepsilon\right) - \tan x\]
\[\frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{\frac{\cos x - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \sin x}{\frac{\sin x}{\frac{\cos x}{\sin x}} + \cos x}}\]

Error

Bits error versus x

Bits error versus eps

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Your Program's Arguments

Results

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Target

Original36.7
Target15.1
Herbie0.4
\[\frac{\sin \varepsilon}{\cos x \cdot \cos \left(x + \varepsilon\right)}\]

Derivation

  1. Initial program 36.7

    \[\tan \left(x + \varepsilon\right) - \tan x\]
  2. Using strategy rm
  3. Applied tan-sum21.6

    \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x\]
  4. Using strategy rm
  5. Applied add-log-exp21.7

    \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \color{blue}{\log \left(e^{\tan x \cdot \tan \varepsilon}\right)}} - \tan x\]
  6. Using strategy rm
  7. Applied tan-quot21.8

    \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \log \left(e^{\tan x \cdot \tan \varepsilon}\right)} - \color{blue}{\frac{\sin x}{\cos x}}\]
  8. Applied frac-sub21.9

    \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot \cos x - \left(1 - \log \left(e^{\tan x \cdot \tan \varepsilon}\right)\right) \cdot \sin x}{\left(1 - \log \left(e^{\tan x \cdot \tan \varepsilon}\right)\right) \cdot \cos x}}\]
  9. Simplified20.5

    \[\leadsto \frac{\color{blue}{\tan \varepsilon \cdot \left(\sin x \cdot \tan x\right) + \left(\cos x \cdot \left(\tan \varepsilon + \tan x\right) - \sin x\right)}}{\left(1 - \log \left(e^{\tan x \cdot \tan \varepsilon}\right)\right) \cdot \cos x}\]
  10. Simplified20.4

    \[\leadsto \frac{\tan \varepsilon \cdot \left(\sin x \cdot \tan x\right) + \left(\cos x \cdot \left(\tan \varepsilon + \tan x\right) - \sin x\right)}{\color{blue}{\cos x - \tan \varepsilon \cdot \left(\cos x \cdot \tan x\right)}}\]
  11. Taylor expanded around -inf 0.4

    \[\leadsto \color{blue}{\frac{\frac{{\left(\sin x\right)}^{2} \cdot \sin \varepsilon}{\cos x \cdot \cos \varepsilon} + \frac{\cos x \cdot \sin \varepsilon}{\cos \varepsilon}}{\cos x - \frac{\sin x \cdot \sin \varepsilon}{\cos \varepsilon}}}\]
  12. Simplified0.4

    \[\leadsto \color{blue}{\frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{\frac{\cos x - \sin x \cdot \frac{\sin \varepsilon}{\cos \varepsilon}}{\cos x + \frac{\sin x}{\frac{\cos x}{\sin x}}}}}\]
  13. Final simplification0.4

    \[\leadsto \frac{\frac{\sin \varepsilon}{\cos \varepsilon}}{\frac{\cos x - \frac{\sin \varepsilon}{\cos \varepsilon} \cdot \sin x}{\frac{\sin x}{\frac{\cos x}{\sin x}} + \cos x}}\]

Runtime

Time bar (total: 50.2s)Debug logProfile

herbie shell --seed 2018277 
(FPCore (x eps)
  :name "2tan (problem 3.3.2)"

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

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