Average Error: 37.0 → 15.4
Time: 8.8s
Precision: 64
\[\tan \left(x + \varepsilon\right) - \tan x\]
\[\begin{array}{l} \mathbf{if}\;\varepsilon \le -6.4253650413344779 \cdot 10^{-20}:\\ \;\;\;\;\frac{\tan x + \tan \varepsilon}{1 - \frac{\left(\tan x \cdot \tan \varepsilon\right) \cdot \left(\sin x \cdot \tan \varepsilon\right)}{\cos x}} \cdot \left(1 + \tan x \cdot \tan \varepsilon\right) - \tan x\\ \mathbf{elif}\;\varepsilon \le 7.60268013552436 \cdot 10^{-69}:\\ \;\;\;\;x \cdot {\varepsilon}^{2} + \left(\varepsilon + {x}^{2} \cdot \varepsilon\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\left(\tan x + \tan \varepsilon\right) \cdot \cos x - \left(1 - \tan x \cdot \tan \varepsilon\right) \cdot \sin x}{\left(1 - \tan x \cdot \tan \varepsilon\right) \cdot \cos x}\\ \end{array}\]
\tan \left(x + \varepsilon\right) - \tan x
\begin{array}{l}
\mathbf{if}\;\varepsilon \le -6.4253650413344779 \cdot 10^{-20}:\\
\;\;\;\;\frac{\tan x + \tan \varepsilon}{1 - \frac{\left(\tan x \cdot \tan \varepsilon\right) \cdot \left(\sin x \cdot \tan \varepsilon\right)}{\cos x}} \cdot \left(1 + \tan x \cdot \tan \varepsilon\right) - \tan x\\

\mathbf{elif}\;\varepsilon \le 7.60268013552436 \cdot 10^{-69}:\\
\;\;\;\;x \cdot {\varepsilon}^{2} + \left(\varepsilon + {x}^{2} \cdot \varepsilon\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{\left(\tan x + \tan \varepsilon\right) \cdot \cos x - \left(1 - \tan x \cdot \tan \varepsilon\right) \cdot \sin x}{\left(1 - \tan x \cdot \tan \varepsilon\right) \cdot \cos x}\\

\end{array}
double f(double x, double eps) {
        double r133153 = x;
        double r133154 = eps;
        double r133155 = r133153 + r133154;
        double r133156 = tan(r133155);
        double r133157 = tan(r133153);
        double r133158 = r133156 - r133157;
        return r133158;
}

double f(double x, double eps) {
        double r133159 = eps;
        double r133160 = -6.425365041334478e-20;
        bool r133161 = r133159 <= r133160;
        double r133162 = x;
        double r133163 = tan(r133162);
        double r133164 = tan(r133159);
        double r133165 = r133163 + r133164;
        double r133166 = 1.0;
        double r133167 = r133163 * r133164;
        double r133168 = sin(r133162);
        double r133169 = r133168 * r133164;
        double r133170 = r133167 * r133169;
        double r133171 = cos(r133162);
        double r133172 = r133170 / r133171;
        double r133173 = r133166 - r133172;
        double r133174 = r133165 / r133173;
        double r133175 = r133166 + r133167;
        double r133176 = r133174 * r133175;
        double r133177 = r133176 - r133163;
        double r133178 = 7.60268013552436e-69;
        bool r133179 = r133159 <= r133178;
        double r133180 = 2.0;
        double r133181 = pow(r133159, r133180);
        double r133182 = r133162 * r133181;
        double r133183 = pow(r133162, r133180);
        double r133184 = r133183 * r133159;
        double r133185 = r133159 + r133184;
        double r133186 = r133182 + r133185;
        double r133187 = r133165 * r133171;
        double r133188 = r133166 - r133167;
        double r133189 = r133188 * r133168;
        double r133190 = r133187 - r133189;
        double r133191 = r133188 * r133171;
        double r133192 = r133190 / r133191;
        double r133193 = r133179 ? r133186 : r133192;
        double r133194 = r133161 ? r133177 : r133193;
        return r133194;
}

Error

Bits error versus x

Bits error versus eps

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original37.0
Target15.0
Herbie15.4
\[\frac{\sin \varepsilon}{\cos x \cdot \cos \left(x + \varepsilon\right)}\]

Derivation

  1. Split input into 3 regimes
  2. if eps < -6.425365041334478e-20

    1. Initial program 30.0

      \[\tan \left(x + \varepsilon\right) - \tan x\]
    2. Using strategy rm
    3. Applied tan-sum1.3

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x\]
    4. Using strategy rm
    5. Applied flip--1.4

      \[\leadsto \frac{\tan x + \tan \varepsilon}{\color{blue}{\frac{1 \cdot 1 - \left(\tan x \cdot \tan \varepsilon\right) \cdot \left(\tan x \cdot \tan \varepsilon\right)}{1 + \tan x \cdot \tan \varepsilon}}} - \tan x\]
    6. Applied associate-/r/1.4

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 \cdot 1 - \left(\tan x \cdot \tan \varepsilon\right) \cdot \left(\tan x \cdot \tan \varepsilon\right)} \cdot \left(1 + \tan x \cdot \tan \varepsilon\right)} - \tan x\]
    7. Simplified1.4

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \left(\tan x \cdot \tan \varepsilon\right) \cdot \left(\tan x \cdot \tan \varepsilon\right)}} \cdot \left(1 + \tan x \cdot \tan \varepsilon\right) - \tan x\]
    8. Using strategy rm
    9. Applied tan-quot1.4

      \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \left(\tan x \cdot \tan \varepsilon\right) \cdot \left(\color{blue}{\frac{\sin x}{\cos x}} \cdot \tan \varepsilon\right)} \cdot \left(1 + \tan x \cdot \tan \varepsilon\right) - \tan x\]
    10. Applied associate-*l/1.4

      \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \left(\tan x \cdot \tan \varepsilon\right) \cdot \color{blue}{\frac{\sin x \cdot \tan \varepsilon}{\cos x}}} \cdot \left(1 + \tan x \cdot \tan \varepsilon\right) - \tan x\]
    11. Applied associate-*r/1.4

      \[\leadsto \frac{\tan x + \tan \varepsilon}{1 - \color{blue}{\frac{\left(\tan x \cdot \tan \varepsilon\right) \cdot \left(\sin x \cdot \tan \varepsilon\right)}{\cos x}}} \cdot \left(1 + \tan x \cdot \tan \varepsilon\right) - \tan x\]

    if -6.425365041334478e-20 < eps < 7.60268013552436e-69

    1. Initial program 46.4

      \[\tan \left(x + \varepsilon\right) - \tan x\]
    2. Using strategy rm
    3. Applied tan-sum46.4

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x\]
    4. Using strategy rm
    5. Applied flip--46.4

      \[\leadsto \frac{\tan x + \tan \varepsilon}{\color{blue}{\frac{1 \cdot 1 - \left(\tan x \cdot \tan \varepsilon\right) \cdot \left(\tan x \cdot \tan \varepsilon\right)}{1 + \tan x \cdot \tan \varepsilon}}} - \tan x\]
    6. Applied associate-/r/46.4

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 \cdot 1 - \left(\tan x \cdot \tan \varepsilon\right) \cdot \left(\tan x \cdot \tan \varepsilon\right)} \cdot \left(1 + \tan x \cdot \tan \varepsilon\right)} - \tan x\]
    7. Simplified46.4

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \left(\tan x \cdot \tan \varepsilon\right) \cdot \left(\tan x \cdot \tan \varepsilon\right)}} \cdot \left(1 + \tan x \cdot \tan \varepsilon\right) - \tan x\]
    8. Taylor expanded around 0 31.2

      \[\leadsto \color{blue}{x \cdot {\varepsilon}^{2} + \left(\varepsilon + {x}^{2} \cdot \varepsilon\right)}\]

    if 7.60268013552436e-69 < eps

    1. Initial program 29.7

      \[\tan \left(x + \varepsilon\right) - \tan x\]
    2. Using strategy rm
    3. Applied tan-quot29.6

      \[\leadsto \tan \left(x + \varepsilon\right) - \color{blue}{\frac{\sin x}{\cos x}}\]
    4. Applied tan-sum5.0

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \frac{\sin x}{\cos x}\]
    5. Applied frac-sub5.1

      \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot \cos x - \left(1 - \tan x \cdot \tan \varepsilon\right) \cdot \sin x}{\left(1 - \tan x \cdot \tan \varepsilon\right) \cdot \cos x}}\]
  3. Recombined 3 regimes into one program.
  4. Final simplification15.4

    \[\leadsto \begin{array}{l} \mathbf{if}\;\varepsilon \le -6.4253650413344779 \cdot 10^{-20}:\\ \;\;\;\;\frac{\tan x + \tan \varepsilon}{1 - \frac{\left(\tan x \cdot \tan \varepsilon\right) \cdot \left(\sin x \cdot \tan \varepsilon\right)}{\cos x}} \cdot \left(1 + \tan x \cdot \tan \varepsilon\right) - \tan x\\ \mathbf{elif}\;\varepsilon \le 7.60268013552436 \cdot 10^{-69}:\\ \;\;\;\;x \cdot {\varepsilon}^{2} + \left(\varepsilon + {x}^{2} \cdot \varepsilon\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\left(\tan x + \tan \varepsilon\right) \cdot \cos x - \left(1 - \tan x \cdot \tan \varepsilon\right) \cdot \sin x}{\left(1 - \tan x \cdot \tan \varepsilon\right) \cdot \cos x}\\ \end{array}\]

Reproduce

herbie shell --seed 2020062 
(FPCore (x eps)
  :name "2tan (problem 3.3.2)"
  :precision binary64

  :herbie-target
  (/ (sin eps) (* (cos x) (cos (+ x eps))))

  (- (tan (+ x eps)) (tan x)))