Average Error: 30.5 → 0.0
Time: 11.3s
Precision: 64
\[\frac{1 - \cos x}{\sin x}\]
\[\tan \left(\frac{x}{2}\right)\]
\frac{1 - \cos x}{\sin x}
\tan \left(\frac{x}{2}\right)
double f(double x) {
        double r2115486 = 1.0;
        double r2115487 = x;
        double r2115488 = cos(r2115487);
        double r2115489 = r2115486 - r2115488;
        double r2115490 = sin(r2115487);
        double r2115491 = r2115489 / r2115490;
        return r2115491;
}

double f(double x) {
        double r2115492 = x;
        double r2115493 = 2.0;
        double r2115494 = r2115492 / r2115493;
        double r2115495 = tan(r2115494);
        return r2115495;
}

Error

Bits error versus x

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original30.5
Target0.0
Herbie0.0
\[\tan \left(\frac{x}{2}\right)\]

Derivation

  1. Initial program 30.5

    \[\frac{1 - \cos x}{\sin x}\]
  2. Simplified0.0

    \[\leadsto \color{blue}{\tan \left(\frac{x}{2}\right)}\]
  3. Final simplification0.0

    \[\leadsto \tan \left(\frac{x}{2}\right)\]

Reproduce

herbie shell --seed 2019149 +o rules:numerics
(FPCore (x)
  :name "tanhf (example 3.4)"
  :herbie-expected 2

  :herbie-target
  (tan (/ x 2))

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