Average Error: 37.0 → 0.4
Time: 51.7s
Precision: 64
Internal Precision: 2368
\[\tan \left(x + \varepsilon\right) - \tan x\]
\[\frac{\sin \varepsilon}{\cos x} \cdot \frac{\frac{\sin x}{\cos x} \cdot \frac{\sin x}{\cos \varepsilon} + \frac{\cos x}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos x} \cdot \frac{\sin x}{\cos \varepsilon}}\]

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

Original37.0
Target15.1
Herbie0.4
\[\frac{\sin \varepsilon}{\cos x \cdot \cos \left(x + \varepsilon\right)}\]

Derivation

  1. Initial program 37.0

    \[\tan \left(x + \varepsilon\right) - \tan x\]
  2. Using strategy rm
  3. Applied tan-quot37.0

    \[\leadsto \tan \left(x + \varepsilon\right) - \color{blue}{\frac{\sin x}{\cos x}}\]
  4. Applied tan-sum21.7

    \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \frac{\sin x}{\cos x}\]
  5. Applied frac-sub21.8

    \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot \cos x - \left(1 - \tan x \cdot \tan \varepsilon\right) \cdot \sin x}{\left(1 - \tan x \cdot \tan \varepsilon\right) \cdot \cos x}}\]
  6. Taylor expanded around -inf 0.4

    \[\leadsto \color{blue}{\frac{\frac{{\left(\sin x\right)}^{2} \cdot \sin \varepsilon}{\cos x \cdot \cos \varepsilon} + \frac{\cos x \cdot \sin \varepsilon}{\cos \varepsilon}}{\cos x \cdot \left(1 - \frac{\sin x \cdot \sin \varepsilon}{\cos x \cdot \cos \varepsilon}\right)}}\]
  7. Simplified0.4

    \[\leadsto \color{blue}{\frac{\sin \varepsilon}{\cos x} \cdot \frac{\frac{\cos x}{\cos \varepsilon} + \frac{\sin x}{\cos \varepsilon} \cdot \frac{\sin x}{\cos x}}{1 - \frac{\sin x}{\cos \varepsilon} \cdot \frac{\sin \varepsilon}{\cos x}}}\]
  8. Final simplification0.4

    \[\leadsto \frac{\sin \varepsilon}{\cos x} \cdot \frac{\frac{\sin x}{\cos x} \cdot \frac{\sin x}{\cos \varepsilon} + \frac{\cos x}{\cos \varepsilon}}{1 - \frac{\sin \varepsilon}{\cos x} \cdot \frac{\sin x}{\cos \varepsilon}}\]

Runtime

Time bar (total: 51.7s)Debug logProfile

herbie shell --seed 2018258 
(FPCore (x eps)
  :name "2tan (problem 3.3.2)"

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

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