Average Error: 30.0 → 0.5
Time: 12.5s
Precision: 64
Internal precision: 2432
\[\frac{1 - \cos x}{\sin x}\]
\[\frac{\sin x}{1} \cdot \frac{1}{\cos x + 1}\]

Error

Bits error versus x

Target

Original30.0
Comparison0.0
Herbie0.5
\[ \tan \left(\frac{x}{2}\right) \]

Derivation

  1. Initial program 30.0

    \[\frac{1 - \cos x}{\sin x}\]
  2. Using strategy rm
  3. Applied flip-- 30.3

    \[\leadsto \frac{\color{blue}{\frac{{1}^2 - {\left(\cos x\right)}^2}{1 + \cos x}}}{\sin x}\]
  4. Applied simplify 15.0

    \[\leadsto \frac{\frac{\color{blue}{\sin x \cdot \sin x}}{1 + \cos x}}{\sin x}\]
  5. Using strategy rm
  6. Applied *-un-lft-identity 15.0

    \[\leadsto \frac{\frac{\sin x \cdot \sin x}{1 + \cos x}}{\color{blue}{1 \cdot \sin x}}\]
  7. Applied *-un-lft-identity 15.0

    \[\leadsto \frac{\frac{\sin x \cdot \sin x}{\color{blue}{1 \cdot \left(1 + \cos x\right)}}}{1 \cdot \sin x}\]
  8. Applied times-frac 14.9

    \[\leadsto \frac{\color{blue}{\frac{\sin x}{1} \cdot \frac{\sin x}{1 + \cos x}}}{1 \cdot \sin x}\]
  9. Applied times-frac 0.5

    \[\leadsto \color{blue}{\frac{\frac{\sin x}{1}}{1} \cdot \frac{\frac{\sin x}{1 + \cos x}}{\sin x}}\]
  10. Applied simplify 0.5

    \[\leadsto \color{blue}{\frac{\sin x}{1}} \cdot \frac{\frac{\sin x}{1 + \cos x}}{\sin x}\]
  11. Applied simplify 0.5

    \[\leadsto \frac{\sin x}{1} \cdot \color{blue}{\frac{1}{\cos x + 1}}\]
  12. Removed slow pow expressions

Runtime

Time bar (total: 12.5s) Debug logProfile

Please include this information when filing a bug report:

herbie shell --seed '#(1064524629 4159152179 2999149171 575749698 4006532819 692958815)'
(FPCore (x)
  :name "tanhf (example 3.4)"
  :herbie-expected 1

  :target
  (tan (/ x 2))

  (/ (- 1 (cos x)) (sin x)))