Average Error: 36.8 → 0.4
Time: 1.0m
Precision: 64
Internal Precision: 2432
\[\tan \left(x + \varepsilon\right) - \tan x\]
\[\frac{\frac{\frac{\sin \varepsilon}{\cos x}}{\cos \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} \cdot \left(\cos x + \sin x \cdot \frac{\sin x}{\cos x}\right)\]

Error

Bits error versus x

Bits error versus eps

Target

Original36.8
Target15.2
Herbie0.4
\[\frac{\sin \varepsilon}{\cos x \cdot \cos \left(x + \varepsilon\right)}\]

Derivation

  1. Initial program 36.8

    \[\tan \left(x + \varepsilon\right) - \tan x\]
  2. Using strategy rm
  3. Applied tan-sum21.5

    \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x\]
  4. Using strategy rm
  5. Applied add-log-exp21.6

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

    \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \log \left(e^{\tan x \cdot \tan \varepsilon}\right)} - \color{blue}{\frac{\sin x}{\cos x}}\]
  8. Applied frac-sub21.7

    \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot \cos x - \left(1 - \log \left(e^{\tan x \cdot \tan \varepsilon}\right)\right) \cdot \sin x}{\left(1 - \log \left(e^{\tan x \cdot \tan \varepsilon}\right)\right) \cdot \cos x}}\]
  9. Applied simplify21.7

    \[\leadsto \frac{\color{blue}{\tan x \cdot \left(\tan \varepsilon \cdot \sin x + \cos x\right) - \left(\sin x - \tan \varepsilon \cdot \cos x\right)}}{\left(1 - \log \left(e^{\tan x \cdot \tan \varepsilon}\right)\right) \cdot \cos x}\]
  10. Applied simplify21.7

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

    \[\leadsto \frac{\color{blue}{\frac{\sin \varepsilon \cdot \cos x}{\cos \varepsilon} + \frac{{\left(\sin x\right)}^{2} \cdot \sin \varepsilon}{\cos \varepsilon \cdot \cos x}}}{\cos x - \left(\cos x \cdot \tan x\right) \cdot \tan \varepsilon}\]
  12. Applied simplify0.4

    \[\leadsto \color{blue}{\frac{\frac{\frac{\sin \varepsilon}{\cos x}}{\cos \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} \cdot \left(\cos x + \sin x \cdot \frac{\sin x}{\cos x}\right)}\]

Runtime

Time bar (total: 1.0m)Debug logProfile

herbie shell --seed '#(1070578969 3140398606 632207097 462683394 1189254563 964980650)' 
(FPCore (x eps)
  :name "2tan (problem 3.3.2)"

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

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