Average Error: 30.8 → 0.0
Time: 11.4s
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 r2341381 = 1.0;
        double r2341382 = x;
        double r2341383 = cos(r2341382);
        double r2341384 = r2341381 - r2341383;
        double r2341385 = sin(r2341382);
        double r2341386 = r2341384 / r2341385;
        return r2341386;
}

double f(double x) {
        double r2341387 = x;
        double r2341388 = 2.0;
        double r2341389 = r2341387 / r2341388;
        double r2341390 = tan(r2341389);
        return r2341390;
}

Error

Bits error versus x

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Your Program's Arguments

Results

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Target

Original30.8
Target0.0
Herbie0.0
\[\tan \left(\frac{x}{2}\right)\]

Derivation

  1. Initial program 30.8

    \[\frac{1 - \cos x}{\sin x}\]
  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 2019158 
(FPCore (x)
  :name "tanhf (example 3.4)"
  :herbie-expected 2

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

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