Average Error: 58.1 → 0.0
Time: 27.7s
Precision: 64
\[\frac{e^{x} - e^{-x}}{e^{x} + e^{-x}}\]
↓
\[\tanh x\]
\frac{e^{x} - e^{-x}}{e^{x} + e^{-x}}
↓
\tanh x
double f(double x) {
        double r48348 = x;
        double r48349 = exp(r48348);
        double r48350 = -r48348;
        double r48351 = exp(r48350);
        double r48352 = r48349 - r48351;
        double r48353 = r48349 + r48351;
        double r48354 = r48352 / r48353;
        return r48354;
}
↓
double f(double x) {
        double r48355 = x;
        double r48356 = tanh(r48355);
        return r48356;
}

Error

Bits error versus x

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Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Initial program 58.1

    \[\frac{e^{x} - e^{-x}}{e^{x} + e^{-x}}\]
  2. Using strategy rm

  3. Applied tanh-undef0.0

    \[\leadsto \color{blue}{\tanh x}\]

  4. Final simplification0.0

    \[\leadsto \tanh x\]

Reproduce

herbie shell --seed 2019304 +o rules:numerics
(FPCore (x)
  :name "Hyperbolic tangent"
  :precision binary64
  (/ (- (exp x) (exp (- x))) (+ (exp x) (exp (- x)))))