Average Error: 58.2 → 0.0
Time: 4.4s
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 r32360 = x;
        double r32361 = exp(r32360);
        double r32362 = -r32360;
        double r32363 = exp(r32362);
        double r32364 = r32361 - r32363;
        double r32365 = r32361 + r32363;
        double r32366 = r32364 / r32365;
        return r32366;
}
↓
double f(double x) {
        double r32367 = x;
        double r32368 = tanh(r32367);
        return r32368;
}

Error

Bits error versus x

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Initial program 58.2

    \[\frac{e^{x} - e^{-x}}{e^{x} + e^{-x}}\]
  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 2020024 
(FPCore (x)
  :name "Hyperbolic tangent"
  :precision binary64
  (/ (- (exp x) (exp (- x))) (+ (exp x) (exp (- x)))))