2tan (problem 3.3.2)

Percentage Accurate: 62.5% → 99.6%
Time: 38.7s
Alternatives: 8
Speedup: 205.0×

Specification

?
\[\left(\left(-10000 \leq x \land x \leq 10000\right) \land 10^{-16} \cdot \left|x\right| < \varepsilon\right) \land \varepsilon < \left|x\right|\]
\[\begin{array}{l} \\ \tan \left(x + \varepsilon\right) - \tan x \end{array} \]
(FPCore (x eps) :precision binary64 (- (tan (+ x eps)) (tan x)))
double code(double x, double eps) {
	return tan((x + eps)) - tan(x);
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = tan((x + eps)) - tan(x)
end function
public static double code(double x, double eps) {
	return Math.tan((x + eps)) - Math.tan(x);
}
def code(x, eps):
	return math.tan((x + eps)) - math.tan(x)
function code(x, eps)
	return Float64(tan(Float64(x + eps)) - tan(x))
end
function tmp = code(x, eps)
	tmp = tan((x + eps)) - tan(x);
end
code[x_, eps_] := N[(N[Tan[N[(x + eps), $MachinePrecision]], $MachinePrecision] - N[Tan[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\tan \left(x + \varepsilon\right) - \tan x
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 8 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 62.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \tan \left(x + \varepsilon\right) - \tan x \end{array} \]
(FPCore (x eps) :precision binary64 (- (tan (+ x eps)) (tan x)))
double code(double x, double eps) {
	return tan((x + eps)) - tan(x);
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = tan((x + eps)) - tan(x)
end function
public static double code(double x, double eps) {
	return Math.tan((x + eps)) - Math.tan(x);
}
def code(x, eps):
	return math.tan((x + eps)) - math.tan(x)
function code(x, eps)
	return Float64(tan(Float64(x + eps)) - tan(x))
end
function tmp = code(x, eps)
	tmp = tan((x + eps)) - tan(x);
end
code[x_, eps_] := N[(N[Tan[N[(x + eps), $MachinePrecision]], $MachinePrecision] - N[Tan[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\tan \left(x + \varepsilon\right) - \tan x
\end{array}

Alternative 1: 99.6% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := {\tan x}^{2}\\ \varepsilon \cdot \left(\left(\log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-\varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\left(\frac{\sin x \cdot \mathsf{hypot}\left(1, \tan x\right)}{\cos x}\right)}^{2}, \mathsf{fma}\left(0.16666666666666666, t\_0, -0.5 + t\_0 \cdot -0.5\right)\right), \sin x \cdot \frac{{\sin x}^{2} \cdot {\cos x}^{-2} + 1}{\cos x}\right)\right)}\right) + 1\right) + \frac{\frac{1 - \cos \left(x \cdot 2\right)}{2}}{{\cos x}^{2}}\right) \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (pow (tan x) 2.0)))
   (*
    eps
    (+
     (+
      (log
       (pow
        (exp eps)
        (fma
         (- eps)
         (+
          0.16666666666666666
          (fma
           -1.0
           (pow (/ (* (sin x) (hypot 1.0 (tan x))) (cos x)) 2.0)
           (fma 0.16666666666666666 t_0 (+ -0.5 (* t_0 -0.5)))))
         (*
          (sin x)
          (/ (+ (* (pow (sin x) 2.0) (pow (cos x) -2.0)) 1.0) (cos x))))))
      1.0)
     (/ (/ (- 1.0 (cos (* x 2.0))) 2.0) (pow (cos x) 2.0))))))
double code(double x, double eps) {
	double t_0 = pow(tan(x), 2.0);
	return eps * ((log(pow(exp(eps), fma(-eps, (0.16666666666666666 + fma(-1.0, pow(((sin(x) * hypot(1.0, tan(x))) / cos(x)), 2.0), fma(0.16666666666666666, t_0, (-0.5 + (t_0 * -0.5))))), (sin(x) * (((pow(sin(x), 2.0) * pow(cos(x), -2.0)) + 1.0) / cos(x)))))) + 1.0) + (((1.0 - cos((x * 2.0))) / 2.0) / pow(cos(x), 2.0)));
}
function code(x, eps)
	t_0 = tan(x) ^ 2.0
	return Float64(eps * Float64(Float64(log((exp(eps) ^ fma(Float64(-eps), Float64(0.16666666666666666 + fma(-1.0, (Float64(Float64(sin(x) * hypot(1.0, tan(x))) / cos(x)) ^ 2.0), fma(0.16666666666666666, t_0, Float64(-0.5 + Float64(t_0 * -0.5))))), Float64(sin(x) * Float64(Float64(Float64((sin(x) ^ 2.0) * (cos(x) ^ -2.0)) + 1.0) / cos(x)))))) + 1.0) + Float64(Float64(Float64(1.0 - cos(Float64(x * 2.0))) / 2.0) / (cos(x) ^ 2.0))))
end
code[x_, eps_] := Block[{t$95$0 = N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision]}, N[(eps * N[(N[(N[Log[N[Power[N[Exp[eps], $MachinePrecision], N[((-eps) * N[(0.16666666666666666 + N[(-1.0 * N[Power[N[(N[(N[Sin[x], $MachinePrecision] * N[Sqrt[1.0 ^ 2 + N[Tan[x], $MachinePrecision] ^ 2], $MachinePrecision]), $MachinePrecision] / N[Cos[x], $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision] + N[(0.16666666666666666 * t$95$0 + N[(-0.5 + N[(t$95$0 * -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[Sin[x], $MachinePrecision] * N[(N[(N[(N[Power[N[Sin[x], $MachinePrecision], 2.0], $MachinePrecision] * N[Power[N[Cos[x], $MachinePrecision], -2.0], $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision] / N[Cos[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] + 1.0), $MachinePrecision] + N[(N[(N[(1.0 - N[Cos[N[(x * 2.0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / 2.0), $MachinePrecision] / N[Power[N[Cos[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := {\tan x}^{2}\\
\varepsilon \cdot \left(\left(\log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-\varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\left(\frac{\sin x \cdot \mathsf{hypot}\left(1, \tan x\right)}{\cos x}\right)}^{2}, \mathsf{fma}\left(0.16666666666666666, t\_0, -0.5 + t\_0 \cdot -0.5\right)\right), \sin x \cdot \frac{{\sin x}^{2} \cdot {\cos x}^{-2} + 1}{\cos x}\right)\right)}\right) + 1\right) + \frac{\frac{1 - \cos \left(x \cdot 2\right)}{2}}{{\cos x}^{2}}\right)
\end{array}
\end{array}
Derivation
  1. Initial program 59.6%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Add Preprocessing
  3. Taylor expanded in eps around 0 99.5%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(0.16666666666666666 + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(-0.5 \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + 0.16666666666666666 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Applied egg-rr99.5%

    \[\leadsto \varepsilon \cdot \left(\left(1 + \color{blue}{\log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\sin x}^{2} \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{{\cos x}^{2}}, \mathsf{fma}\left(0.16666666666666666, {\sin x}^{2} \cdot {\cos x}^{-2}, \left(1 + {\sin x}^{2} \cdot {\cos x}^{-2}\right) \cdot -0.5\right)\right), \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
  5. Step-by-step derivation
    1. unpow299.5%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\sin x}^{2} \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{{\cos x}^{2}}, \mathsf{fma}\left(0.16666666666666666, {\sin x}^{2} \cdot {\cos x}^{-2}, \left(1 + {\sin x}^{2} \cdot {\cos x}^{-2}\right) \cdot -0.5\right)\right), \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)\right) - -1 \cdot \frac{\color{blue}{\sin x \cdot \sin x}}{{\cos x}^{2}}\right) \]
    2. sin-mult99.5%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\sin x}^{2} \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{{\cos x}^{2}}, \mathsf{fma}\left(0.16666666666666666, {\sin x}^{2} \cdot {\cos x}^{-2}, \left(1 + {\sin x}^{2} \cdot {\cos x}^{-2}\right) \cdot -0.5\right)\right), \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)\right) - -1 \cdot \frac{\color{blue}{\frac{\cos \left(x - x\right) - \cos \left(x + x\right)}{2}}}{{\cos x}^{2}}\right) \]
  6. Applied egg-rr99.5%

    \[\leadsto \varepsilon \cdot \left(\left(1 + \log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\sin x}^{2} \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{{\cos x}^{2}}, \mathsf{fma}\left(0.16666666666666666, {\sin x}^{2} \cdot {\cos x}^{-2}, \left(1 + {\sin x}^{2} \cdot {\cos x}^{-2}\right) \cdot -0.5\right)\right), \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)\right) - -1 \cdot \frac{\color{blue}{\frac{\cos \left(x - x\right) - \cos \left(x + x\right)}{2}}}{{\cos x}^{2}}\right) \]
  7. Step-by-step derivation
    1. +-inverses99.5%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\sin x}^{2} \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{{\cos x}^{2}}, \mathsf{fma}\left(0.16666666666666666, {\sin x}^{2} \cdot {\cos x}^{-2}, \left(1 + {\sin x}^{2} \cdot {\cos x}^{-2}\right) \cdot -0.5\right)\right), \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)\right) - -1 \cdot \frac{\frac{\cos \color{blue}{0} - \cos \left(x + x\right)}{2}}{{\cos x}^{2}}\right) \]
    2. cos-099.5%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\sin x}^{2} \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{{\cos x}^{2}}, \mathsf{fma}\left(0.16666666666666666, {\sin x}^{2} \cdot {\cos x}^{-2}, \left(1 + {\sin x}^{2} \cdot {\cos x}^{-2}\right) \cdot -0.5\right)\right), \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)\right) - -1 \cdot \frac{\frac{\color{blue}{1} - \cos \left(x + x\right)}{2}}{{\cos x}^{2}}\right) \]
    3. count-299.5%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\sin x}^{2} \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{{\cos x}^{2}}, \mathsf{fma}\left(0.16666666666666666, {\sin x}^{2} \cdot {\cos x}^{-2}, \left(1 + {\sin x}^{2} \cdot {\cos x}^{-2}\right) \cdot -0.5\right)\right), \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)\right) - -1 \cdot \frac{\frac{1 - \cos \color{blue}{\left(2 \cdot x\right)}}{2}}{{\cos x}^{2}}\right) \]
    4. *-commutative99.5%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\sin x}^{2} \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{{\cos x}^{2}}, \mathsf{fma}\left(0.16666666666666666, {\sin x}^{2} \cdot {\cos x}^{-2}, \left(1 + {\sin x}^{2} \cdot {\cos x}^{-2}\right) \cdot -0.5\right)\right), \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)\right) - -1 \cdot \frac{\frac{1 - \cos \color{blue}{\left(x \cdot 2\right)}}{2}}{{\cos x}^{2}}\right) \]
  8. Simplified99.5%

    \[\leadsto \varepsilon \cdot \left(\left(1 + \log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\sin x}^{2} \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{{\cos x}^{2}}, \mathsf{fma}\left(0.16666666666666666, {\sin x}^{2} \cdot {\cos x}^{-2}, \left(1 + {\sin x}^{2} \cdot {\cos x}^{-2}\right) \cdot -0.5\right)\right), \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)\right) - -1 \cdot \frac{\color{blue}{\frac{1 - \cos \left(x \cdot 2\right)}{2}}}{{\cos x}^{2}}\right) \]
  9. Applied egg-rr99.5%

    \[\leadsto \varepsilon \cdot \left(\left(1 + \log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, \color{blue}{1 \cdot \left(0.16666666666666666 + \mathsf{fma}\left(-1, {\left(\sin x \cdot \frac{\mathsf{hypot}\left(1, \tan x\right)}{\cos x}\right)}^{2}, \mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \left(1 + {\tan x}^{2}\right) \cdot -0.5\right)\right)\right)}, \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)\right) - -1 \cdot \frac{\frac{1 - \cos \left(x \cdot 2\right)}{2}}{{\cos x}^{2}}\right) \]
  10. Step-by-step derivation
    1. *-lft-identity99.5%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, \color{blue}{0.16666666666666666 + \mathsf{fma}\left(-1, {\left(\sin x \cdot \frac{\mathsf{hypot}\left(1, \tan x\right)}{\cos x}\right)}^{2}, \mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \left(1 + {\tan x}^{2}\right) \cdot -0.5\right)\right)}, \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)\right) - -1 \cdot \frac{\frac{1 - \cos \left(x \cdot 2\right)}{2}}{{\cos x}^{2}}\right) \]
    2. associate-*r/99.5%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\color{blue}{\left(\frac{\sin x \cdot \mathsf{hypot}\left(1, \tan x\right)}{\cos x}\right)}}^{2}, \mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \left(1 + {\tan x}^{2}\right) \cdot -0.5\right)\right), \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)\right) - -1 \cdot \frac{\frac{1 - \cos \left(x \cdot 2\right)}{2}}{{\cos x}^{2}}\right) \]
    3. *-commutative99.5%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\left(\frac{\sin x \cdot \mathsf{hypot}\left(1, \tan x\right)}{\cos x}\right)}^{2}, \mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \color{blue}{-0.5 \cdot \left(1 + {\tan x}^{2}\right)}\right)\right), \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)\right) - -1 \cdot \frac{\frac{1 - \cos \left(x \cdot 2\right)}{2}}{{\cos x}^{2}}\right) \]
    4. distribute-rgt-in99.5%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\left(\frac{\sin x \cdot \mathsf{hypot}\left(1, \tan x\right)}{\cos x}\right)}^{2}, \mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \color{blue}{1 \cdot -0.5 + {\tan x}^{2} \cdot -0.5}\right)\right), \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)\right) - -1 \cdot \frac{\frac{1 - \cos \left(x \cdot 2\right)}{2}}{{\cos x}^{2}}\right) \]
    5. metadata-eval99.5%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\left(\frac{\sin x \cdot \mathsf{hypot}\left(1, \tan x\right)}{\cos x}\right)}^{2}, \mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, \color{blue}{-0.5} + {\tan x}^{2} \cdot -0.5\right)\right), \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)\right) - -1 \cdot \frac{\frac{1 - \cos \left(x \cdot 2\right)}{2}}{{\cos x}^{2}}\right) \]
  11. Simplified99.5%

    \[\leadsto \varepsilon \cdot \left(\left(1 + \log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-1 \cdot \varepsilon, \color{blue}{0.16666666666666666 + \mathsf{fma}\left(-1, {\left(\frac{\sin x \cdot \mathsf{hypot}\left(1, \tan x\right)}{\cos x}\right)}^{2}, \mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, -0.5 + {\tan x}^{2} \cdot -0.5\right)\right)}, \sin x \cdot \frac{1 + {\sin x}^{2} \cdot {\cos x}^{-2}}{\cos x}\right)\right)}\right)\right) - -1 \cdot \frac{\frac{1 - \cos \left(x \cdot 2\right)}{2}}{{\cos x}^{2}}\right) \]
  12. Final simplification99.5%

    \[\leadsto \varepsilon \cdot \left(\left(\log \left({\left(e^{\varepsilon}\right)}^{\left(\mathsf{fma}\left(-\varepsilon, 0.16666666666666666 + \mathsf{fma}\left(-1, {\left(\frac{\sin x \cdot \mathsf{hypot}\left(1, \tan x\right)}{\cos x}\right)}^{2}, \mathsf{fma}\left(0.16666666666666666, {\tan x}^{2}, -0.5 + {\tan x}^{2} \cdot -0.5\right)\right), \sin x \cdot \frac{{\sin x}^{2} \cdot {\cos x}^{-2} + 1}{\cos x}\right)\right)}\right) + 1\right) + \frac{\frac{1 - \cos \left(x \cdot 2\right)}{2}}{{\cos x}^{2}}\right) \]
  13. Add Preprocessing

Alternative 2: 99.6% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{{\sin x}^{2}}{{\cos x}^{2}}\\ \varepsilon \cdot \left(t\_0 + \left(\varepsilon \cdot \left(\varepsilon \cdot \left(0.3333333333333333 + \left(t\_0 + \left(\frac{{\sin x}^{4}}{{\cos x}^{4}} - t\_0 \cdot -0.3333333333333333\right)\right)\right) + \left(\frac{\sin x}{\cos x} + \frac{{\sin x}^{3}}{{\cos x}^{3}}\right)\right) + 1\right)\right) \end{array} \end{array} \]
(FPCore (x eps)
 :precision binary64
 (let* ((t_0 (/ (pow (sin x) 2.0) (pow (cos x) 2.0))))
   (*
    eps
    (+
     t_0
     (+
      (*
       eps
       (+
        (*
         eps
         (+
          0.3333333333333333
          (+
           t_0
           (-
            (/ (pow (sin x) 4.0) (pow (cos x) 4.0))
            (* t_0 -0.3333333333333333)))))
        (+ (/ (sin x) (cos x)) (/ (pow (sin x) 3.0) (pow (cos x) 3.0)))))
      1.0)))))
double code(double x, double eps) {
	double t_0 = pow(sin(x), 2.0) / pow(cos(x), 2.0);
	return eps * (t_0 + ((eps * ((eps * (0.3333333333333333 + (t_0 + ((pow(sin(x), 4.0) / pow(cos(x), 4.0)) - (t_0 * -0.3333333333333333))))) + ((sin(x) / cos(x)) + (pow(sin(x), 3.0) / pow(cos(x), 3.0))))) + 1.0));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    real(8) :: t_0
    t_0 = (sin(x) ** 2.0d0) / (cos(x) ** 2.0d0)
    code = eps * (t_0 + ((eps * ((eps * (0.3333333333333333d0 + (t_0 + (((sin(x) ** 4.0d0) / (cos(x) ** 4.0d0)) - (t_0 * (-0.3333333333333333d0)))))) + ((sin(x) / cos(x)) + ((sin(x) ** 3.0d0) / (cos(x) ** 3.0d0))))) + 1.0d0))
end function
public static double code(double x, double eps) {
	double t_0 = Math.pow(Math.sin(x), 2.0) / Math.pow(Math.cos(x), 2.0);
	return eps * (t_0 + ((eps * ((eps * (0.3333333333333333 + (t_0 + ((Math.pow(Math.sin(x), 4.0) / Math.pow(Math.cos(x), 4.0)) - (t_0 * -0.3333333333333333))))) + ((Math.sin(x) / Math.cos(x)) + (Math.pow(Math.sin(x), 3.0) / Math.pow(Math.cos(x), 3.0))))) + 1.0));
}
def code(x, eps):
	t_0 = math.pow(math.sin(x), 2.0) / math.pow(math.cos(x), 2.0)
	return eps * (t_0 + ((eps * ((eps * (0.3333333333333333 + (t_0 + ((math.pow(math.sin(x), 4.0) / math.pow(math.cos(x), 4.0)) - (t_0 * -0.3333333333333333))))) + ((math.sin(x) / math.cos(x)) + (math.pow(math.sin(x), 3.0) / math.pow(math.cos(x), 3.0))))) + 1.0))
function code(x, eps)
	t_0 = Float64((sin(x) ^ 2.0) / (cos(x) ^ 2.0))
	return Float64(eps * Float64(t_0 + Float64(Float64(eps * Float64(Float64(eps * Float64(0.3333333333333333 + Float64(t_0 + Float64(Float64((sin(x) ^ 4.0) / (cos(x) ^ 4.0)) - Float64(t_0 * -0.3333333333333333))))) + Float64(Float64(sin(x) / cos(x)) + Float64((sin(x) ^ 3.0) / (cos(x) ^ 3.0))))) + 1.0)))
end
function tmp = code(x, eps)
	t_0 = (sin(x) ^ 2.0) / (cos(x) ^ 2.0);
	tmp = eps * (t_0 + ((eps * ((eps * (0.3333333333333333 + (t_0 + (((sin(x) ^ 4.0) / (cos(x) ^ 4.0)) - (t_0 * -0.3333333333333333))))) + ((sin(x) / cos(x)) + ((sin(x) ^ 3.0) / (cos(x) ^ 3.0))))) + 1.0));
end
code[x_, eps_] := Block[{t$95$0 = N[(N[Power[N[Sin[x], $MachinePrecision], 2.0], $MachinePrecision] / N[Power[N[Cos[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]}, N[(eps * N[(t$95$0 + N[(N[(eps * N[(N[(eps * N[(0.3333333333333333 + N[(t$95$0 + N[(N[(N[Power[N[Sin[x], $MachinePrecision], 4.0], $MachinePrecision] / N[Power[N[Cos[x], $MachinePrecision], 4.0], $MachinePrecision]), $MachinePrecision] - N[(t$95$0 * -0.3333333333333333), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[Sin[x], $MachinePrecision] / N[Cos[x], $MachinePrecision]), $MachinePrecision] + N[(N[Power[N[Sin[x], $MachinePrecision], 3.0], $MachinePrecision] / N[Power[N[Cos[x], $MachinePrecision], 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{{\sin x}^{2}}{{\cos x}^{2}}\\
\varepsilon \cdot \left(t\_0 + \left(\varepsilon \cdot \left(\varepsilon \cdot \left(0.3333333333333333 + \left(t\_0 + \left(\frac{{\sin x}^{4}}{{\cos x}^{4}} - t\_0 \cdot -0.3333333333333333\right)\right)\right) + \left(\frac{\sin x}{\cos x} + \frac{{\sin x}^{3}}{{\cos x}^{3}}\right)\right) + 1\right)\right)
\end{array}
\end{array}
Derivation
  1. Initial program 59.6%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. tan-sum60.0%

      \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    2. div-inv60.0%

      \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    3. fma-neg60.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
  4. Applied egg-rr60.0%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\tan x + \tan \varepsilon, \frac{1}{1 - \tan x \cdot \tan \varepsilon}, -\tan x\right)} \]
  5. Step-by-step derivation
    1. fma-neg60.0%

      \[\leadsto \color{blue}{\left(\tan x + \tan \varepsilon\right) \cdot \frac{1}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
    2. associate-*r/60.0%

      \[\leadsto \color{blue}{\frac{\left(\tan x + \tan \varepsilon\right) \cdot 1}{1 - \tan x \cdot \tan \varepsilon}} - \tan x \]
    3. *-rgt-identity60.0%

      \[\leadsto \frac{\color{blue}{\tan x + \tan \varepsilon}}{1 - \tan x \cdot \tan \varepsilon} - \tan x \]
  6. Simplified60.0%

    \[\leadsto \color{blue}{\frac{\tan x + \tan \varepsilon}{1 - \tan x \cdot \tan \varepsilon} - \tan x} \]
  7. Taylor expanded in eps around 0 99.5%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\varepsilon \cdot \left(0.3333333333333333 - \left(-1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}} + \left(-1 \cdot \frac{{\sin x}^{4}}{{\cos x}^{4}} + -0.3333333333333333 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right) - \left(-1 \cdot \frac{\sin x}{\cos x} + -1 \cdot \frac{{\sin x}^{3}}{{\cos x}^{3}}\right)\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  8. Final simplification99.5%

    \[\leadsto \varepsilon \cdot \left(\frac{{\sin x}^{2}}{{\cos x}^{2}} + \left(\varepsilon \cdot \left(\varepsilon \cdot \left(0.3333333333333333 + \left(\frac{{\sin x}^{2}}{{\cos x}^{2}} + \left(\frac{{\sin x}^{4}}{{\cos x}^{4}} - \frac{{\sin x}^{2}}{{\cos x}^{2}} \cdot -0.3333333333333333\right)\right)\right) + \left(\frac{\sin x}{\cos x} + \frac{{\sin x}^{3}}{{\cos x}^{3}}\right)\right) + 1\right)\right) \]
  9. Add Preprocessing

Alternative 3: 99.5% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \varepsilon \cdot \left(\frac{{\sin x}^{2}}{{\cos x}^{2}} + \left(\varepsilon \cdot \mathsf{fma}\left(\varepsilon, 0.3333333333333333, \tan x + {\tan x}^{3}\right) + 1\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (*
  eps
  (+
   (/ (pow (sin x) 2.0) (pow (cos x) 2.0))
   (+
    (* eps (fma eps 0.3333333333333333 (+ (tan x) (pow (tan x) 3.0))))
    1.0))))
double code(double x, double eps) {
	return eps * ((pow(sin(x), 2.0) / pow(cos(x), 2.0)) + ((eps * fma(eps, 0.3333333333333333, (tan(x) + pow(tan(x), 3.0)))) + 1.0));
}
function code(x, eps)
	return Float64(eps * Float64(Float64((sin(x) ^ 2.0) / (cos(x) ^ 2.0)) + Float64(Float64(eps * fma(eps, 0.3333333333333333, Float64(tan(x) + (tan(x) ^ 3.0)))) + 1.0)))
end
code[x_, eps_] := N[(eps * N[(N[(N[Power[N[Sin[x], $MachinePrecision], 2.0], $MachinePrecision] / N[Power[N[Cos[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] + N[(N[(eps * N[(eps * 0.3333333333333333 + N[(N[Tan[x], $MachinePrecision] + N[Power[N[Tan[x], $MachinePrecision], 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\varepsilon \cdot \left(\frac{{\sin x}^{2}}{{\cos x}^{2}} + \left(\varepsilon \cdot \mathsf{fma}\left(\varepsilon, 0.3333333333333333, \tan x + {\tan x}^{3}\right) + 1\right)\right)
\end{array}
Derivation
  1. Initial program 59.6%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Add Preprocessing
  3. Taylor expanded in eps around 0 99.5%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(0.16666666666666666 + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(-0.5 \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + 0.16666666666666666 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Taylor expanded in x around 0 99.3%

    \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \color{blue}{-0.3333333333333333}\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
  5. Applied egg-rr99.3%

    \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \color{blue}{\left(\mathsf{fma}\left(\varepsilon \cdot -0.3333333333333333, -1, -\left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right) \cdot 1\right) + \mathsf{fma}\left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x, 1, \left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right) \cdot 1\right)\right)}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
  6. Step-by-step derivation
    1. fma-undefine99.3%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\color{blue}{\left(\left(\varepsilon \cdot -0.3333333333333333\right) \cdot -1 + \left(-\left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right) \cdot 1\right)\right)} + \mathsf{fma}\left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x, 1, \left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right) \cdot 1\right)\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    2. distribute-rgt-neg-in99.3%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\left(\left(\varepsilon \cdot -0.3333333333333333\right) \cdot -1 + \color{blue}{\left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right) \cdot \left(-1\right)}\right) + \mathsf{fma}\left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x, 1, \left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right) \cdot 1\right)\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    3. metadata-eval99.3%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\left(\left(\varepsilon \cdot -0.3333333333333333\right) \cdot -1 + \left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right) \cdot \color{blue}{-1}\right) + \mathsf{fma}\left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x, 1, \left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right) \cdot 1\right)\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    4. distribute-rgt-in99.3%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\color{blue}{-1 \cdot \left(\varepsilon \cdot -0.3333333333333333 + \frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right)} + \mathsf{fma}\left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x, 1, \left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right) \cdot 1\right)\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    5. fma-define99.3%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \color{blue}{\mathsf{fma}\left(\varepsilon, -0.3333333333333333, \frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right)} + \mathsf{fma}\left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x, 1, \left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right) \cdot 1\right)\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    6. neg-mul-199.3%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\color{blue}{\left(-\mathsf{fma}\left(\varepsilon, -0.3333333333333333, \frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right)\right)} + \mathsf{fma}\left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x, 1, \left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right) \cdot 1\right)\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    7. neg-sub099.3%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\color{blue}{\left(0 - \mathsf{fma}\left(\varepsilon, -0.3333333333333333, \frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right)\right)} + \mathsf{fma}\left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x, 1, \left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right) \cdot 1\right)\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    8. fma-undefine99.3%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\left(0 - \mathsf{fma}\left(\varepsilon, -0.3333333333333333, \frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right)\right) + \color{blue}{\left(\left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right) \cdot 1 + \left(\frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right) \cdot 1\right)}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
  7. Simplified99.3%

    \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \color{blue}{\mathsf{fma}\left(\varepsilon, 0.3333333333333333, \tan x + {\tan x}^{3}\right)}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
  8. Final simplification99.3%

    \[\leadsto \varepsilon \cdot \left(\frac{{\sin x}^{2}}{{\cos x}^{2}} + \left(\varepsilon \cdot \mathsf{fma}\left(\varepsilon, 0.3333333333333333, \tan x + {\tan x}^{3}\right) + 1\right)\right) \]
  9. Add Preprocessing

Alternative 4: 99.5% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \varepsilon \cdot \left(\frac{{\sin x}^{2}}{{\cos x}^{2}} + \left(\varepsilon \cdot \left(\varepsilon \cdot -0.3333333333333333 + \tan x \cdot \left({\tan x}^{2} + 1\right)\right) + 1\right)\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (*
  eps
  (+
   (/ (pow (sin x) 2.0) (pow (cos x) 2.0))
   (+
    (*
     eps
     (+ (* eps -0.3333333333333333) (* (tan x) (+ (pow (tan x) 2.0) 1.0))))
    1.0))))
double code(double x, double eps) {
	return eps * ((pow(sin(x), 2.0) / pow(cos(x), 2.0)) + ((eps * ((eps * -0.3333333333333333) + (tan(x) * (pow(tan(x), 2.0) + 1.0)))) + 1.0));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = eps * (((sin(x) ** 2.0d0) / (cos(x) ** 2.0d0)) + ((eps * ((eps * (-0.3333333333333333d0)) + (tan(x) * ((tan(x) ** 2.0d0) + 1.0d0)))) + 1.0d0))
end function
public static double code(double x, double eps) {
	return eps * ((Math.pow(Math.sin(x), 2.0) / Math.pow(Math.cos(x), 2.0)) + ((eps * ((eps * -0.3333333333333333) + (Math.tan(x) * (Math.pow(Math.tan(x), 2.0) + 1.0)))) + 1.0));
}
def code(x, eps):
	return eps * ((math.pow(math.sin(x), 2.0) / math.pow(math.cos(x), 2.0)) + ((eps * ((eps * -0.3333333333333333) + (math.tan(x) * (math.pow(math.tan(x), 2.0) + 1.0)))) + 1.0))
function code(x, eps)
	return Float64(eps * Float64(Float64((sin(x) ^ 2.0) / (cos(x) ^ 2.0)) + Float64(Float64(eps * Float64(Float64(eps * -0.3333333333333333) + Float64(tan(x) * Float64((tan(x) ^ 2.0) + 1.0)))) + 1.0)))
end
function tmp = code(x, eps)
	tmp = eps * (((sin(x) ^ 2.0) / (cos(x) ^ 2.0)) + ((eps * ((eps * -0.3333333333333333) + (tan(x) * ((tan(x) ^ 2.0) + 1.0)))) + 1.0));
end
code[x_, eps_] := N[(eps * N[(N[(N[Power[N[Sin[x], $MachinePrecision], 2.0], $MachinePrecision] / N[Power[N[Cos[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] + N[(N[(eps * N[(N[(eps * -0.3333333333333333), $MachinePrecision] + N[(N[Tan[x], $MachinePrecision] * N[(N[Power[N[Tan[x], $MachinePrecision], 2.0], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\varepsilon \cdot \left(\frac{{\sin x}^{2}}{{\cos x}^{2}} + \left(\varepsilon \cdot \left(\varepsilon \cdot -0.3333333333333333 + \tan x \cdot \left({\tan x}^{2} + 1\right)\right) + 1\right)\right)
\end{array}
Derivation
  1. Initial program 59.6%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Add Preprocessing
  3. Taylor expanded in eps around 0 99.5%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \left(0.16666666666666666 + \left(-1 \cdot \frac{{\sin x}^{2} \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{{\cos x}^{2}} + \left(-0.5 \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) + 0.16666666666666666 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)\right)\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Taylor expanded in x around 0 99.3%

    \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(-1 \cdot \left(\varepsilon \cdot \color{blue}{-0.3333333333333333}\right) - -1 \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
  5. Step-by-step derivation
    1. cancel-sign-sub-inv99.3%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \color{blue}{\left(-1 \cdot \left(\varepsilon \cdot -0.3333333333333333\right) + \left(--1\right) \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    2. add-sqr-sqrt99.3%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\color{blue}{\sqrt{-1 \cdot \left(\varepsilon \cdot -0.3333333333333333\right)} \cdot \sqrt{-1 \cdot \left(\varepsilon \cdot -0.3333333333333333\right)}} + \left(--1\right) \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    3. sqrt-unprod99.3%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\color{blue}{\sqrt{\left(-1 \cdot \left(\varepsilon \cdot -0.3333333333333333\right)\right) \cdot \left(-1 \cdot \left(\varepsilon \cdot -0.3333333333333333\right)\right)}} + \left(--1\right) \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    4. mul-1-neg99.3%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\sqrt{\color{blue}{\left(-\varepsilon \cdot -0.3333333333333333\right)} \cdot \left(-1 \cdot \left(\varepsilon \cdot -0.3333333333333333\right)\right)} + \left(--1\right) \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    5. mul-1-neg99.3%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\sqrt{\left(-\varepsilon \cdot -0.3333333333333333\right) \cdot \color{blue}{\left(-\varepsilon \cdot -0.3333333333333333\right)}} + \left(--1\right) \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    6. sqr-neg99.3%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\sqrt{\color{blue}{\left(\varepsilon \cdot -0.3333333333333333\right) \cdot \left(\varepsilon \cdot -0.3333333333333333\right)}} + \left(--1\right) \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    7. sqrt-unprod0.0%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\color{blue}{\sqrt{\varepsilon \cdot -0.3333333333333333} \cdot \sqrt{\varepsilon \cdot -0.3333333333333333}} + \left(--1\right) \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    8. add-sqr-sqrt99.2%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\color{blue}{\varepsilon \cdot -0.3333333333333333} + \left(--1\right) \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    9. metadata-eval99.2%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\varepsilon \cdot -0.3333333333333333 + \color{blue}{1} \cdot \frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    10. *-un-lft-identity99.2%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\varepsilon \cdot -0.3333333333333333 + \color{blue}{\frac{\sin x \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}{\cos x}}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    11. *-commutative99.2%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\varepsilon \cdot -0.3333333333333333 + \frac{\color{blue}{\left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \cdot \sin x}}{\cos x}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    12. *-un-lft-identity99.2%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\varepsilon \cdot -0.3333333333333333 + \frac{\left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \cdot \sin x}{\color{blue}{1 \cdot \cos x}}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
    13. times-frac99.2%

      \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \left(\varepsilon \cdot -0.3333333333333333 + \color{blue}{\frac{1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}}{1} \cdot \frac{\sin x}{\cos x}}\right)\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
  6. Applied egg-rr99.2%

    \[\leadsto \varepsilon \cdot \left(\left(1 + \varepsilon \cdot \color{blue}{\left(\varepsilon \cdot -0.3333333333333333 + \frac{1 + {\tan x}^{2}}{1} \cdot \tan x\right)}\right) - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right) \]
  7. Final simplification99.2%

    \[\leadsto \varepsilon \cdot \left(\frac{{\sin x}^{2}}{{\cos x}^{2}} + \left(\varepsilon \cdot \left(\varepsilon \cdot -0.3333333333333333 + \tan x \cdot \left({\tan x}^{2} + 1\right)\right) + 1\right)\right) \]
  8. Add Preprocessing

Alternative 5: 99.1% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \varepsilon \cdot \left(\frac{{\sin x}^{2}}{{\cos x}^{2}} + 1\right) \end{array} \]
(FPCore (x eps)
 :precision binary64
 (* eps (+ (/ (pow (sin x) 2.0) (pow (cos x) 2.0)) 1.0)))
double code(double x, double eps) {
	return eps * ((pow(sin(x), 2.0) / pow(cos(x), 2.0)) + 1.0);
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = eps * (((sin(x) ** 2.0d0) / (cos(x) ** 2.0d0)) + 1.0d0)
end function
public static double code(double x, double eps) {
	return eps * ((Math.pow(Math.sin(x), 2.0) / Math.pow(Math.cos(x), 2.0)) + 1.0);
}
def code(x, eps):
	return eps * ((math.pow(math.sin(x), 2.0) / math.pow(math.cos(x), 2.0)) + 1.0)
function code(x, eps)
	return Float64(eps * Float64(Float64((sin(x) ^ 2.0) / (cos(x) ^ 2.0)) + 1.0))
end
function tmp = code(x, eps)
	tmp = eps * (((sin(x) ^ 2.0) / (cos(x) ^ 2.0)) + 1.0);
end
code[x_, eps_] := N[(eps * N[(N[(N[Power[N[Sin[x], $MachinePrecision], 2.0], $MachinePrecision] / N[Power[N[Cos[x], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\varepsilon \cdot \left(\frac{{\sin x}^{2}}{{\cos x}^{2}} + 1\right)
\end{array}
Derivation
  1. Initial program 59.6%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Add Preprocessing
  3. Taylor expanded in eps around 0 98.8%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(1 - -1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  4. Step-by-step derivation
    1. sub-neg98.8%

      \[\leadsto \varepsilon \cdot \color{blue}{\left(1 + \left(--1 \cdot \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)\right)} \]
    2. mul-1-neg98.8%

      \[\leadsto \varepsilon \cdot \left(1 + \left(-\color{blue}{\left(-\frac{{\sin x}^{2}}{{\cos x}^{2}}\right)}\right)\right) \]
    3. remove-double-neg98.8%

      \[\leadsto \varepsilon \cdot \left(1 + \color{blue}{\frac{{\sin x}^{2}}{{\cos x}^{2}}}\right) \]
  5. Simplified98.8%

    \[\leadsto \color{blue}{\varepsilon \cdot \left(1 + \frac{{\sin x}^{2}}{{\cos x}^{2}}\right)} \]
  6. Final simplification98.8%

    \[\leadsto \varepsilon \cdot \left(\frac{{\sin x}^{2}}{{\cos x}^{2}} + 1\right) \]
  7. Add Preprocessing

Alternative 6: 98.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\sin \varepsilon}{\cos \varepsilon} \end{array} \]
(FPCore (x eps) :precision binary64 (/ (sin eps) (cos eps)))
double code(double x, double eps) {
	return sin(eps) / cos(eps);
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = sin(eps) / cos(eps)
end function
public static double code(double x, double eps) {
	return Math.sin(eps) / Math.cos(eps);
}
def code(x, eps):
	return math.sin(eps) / math.cos(eps)
function code(x, eps)
	return Float64(sin(eps) / cos(eps))
end
function tmp = code(x, eps)
	tmp = sin(eps) / cos(eps);
end
code[x_, eps_] := N[(N[Sin[eps], $MachinePrecision] / N[Cos[eps], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\sin \varepsilon}{\cos \varepsilon}
\end{array}
Derivation
  1. Initial program 59.6%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0 97.2%

    \[\leadsto \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon}} \]
  4. Final simplification97.2%

    \[\leadsto \frac{\sin \varepsilon}{\cos \varepsilon} \]
  5. Add Preprocessing

Alternative 7: 98.1% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \tan \varepsilon \end{array} \]
(FPCore (x eps) :precision binary64 (tan eps))
double code(double x, double eps) {
	return tan(eps);
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = tan(eps)
end function
public static double code(double x, double eps) {
	return Math.tan(eps);
}
def code(x, eps):
	return math.tan(eps)
function code(x, eps)
	return tan(eps)
end
function tmp = code(x, eps)
	tmp = tan(eps);
end
code[x_, eps_] := N[Tan[eps], $MachinePrecision]
\begin{array}{l}

\\
\tan \varepsilon
\end{array}
Derivation
  1. Initial program 59.6%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0 97.2%

    \[\leadsto \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon}} \]
  4. Step-by-step derivation
    1. tan-quot97.2%

      \[\leadsto \color{blue}{\tan \varepsilon} \]
    2. *-un-lft-identity97.2%

      \[\leadsto \color{blue}{1 \cdot \tan \varepsilon} \]
  5. Applied egg-rr97.2%

    \[\leadsto \color{blue}{1 \cdot \tan \varepsilon} \]
  6. Step-by-step derivation
    1. *-lft-identity97.2%

      \[\leadsto \color{blue}{\tan \varepsilon} \]
  7. Simplified97.2%

    \[\leadsto \color{blue}{\tan \varepsilon} \]
  8. Final simplification97.2%

    \[\leadsto \tan \varepsilon \]
  9. Add Preprocessing

Alternative 8: 98.1% accurate, 205.0× speedup?

\[\begin{array}{l} \\ \varepsilon \end{array} \]
(FPCore (x eps) :precision binary64 eps)
double code(double x, double eps) {
	return eps;
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = eps
end function
public static double code(double x, double eps) {
	return eps;
}
def code(x, eps):
	return eps
function code(x, eps)
	return eps
end
function tmp = code(x, eps)
	tmp = eps;
end
code[x_, eps_] := eps
\begin{array}{l}

\\
\varepsilon
\end{array}
Derivation
  1. Initial program 59.6%

    \[\tan \left(x + \varepsilon\right) - \tan x \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0 97.2%

    \[\leadsto \color{blue}{\frac{\sin \varepsilon}{\cos \varepsilon}} \]
  4. Taylor expanded in eps around 0 97.2%

    \[\leadsto \color{blue}{\varepsilon} \]
  5. Final simplification97.2%

    \[\leadsto \varepsilon \]
  6. Add Preprocessing

Developer target: 99.9% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \frac{\sin \varepsilon}{\cos x \cdot \cos \left(x + \varepsilon\right)} \end{array} \]
(FPCore (x eps) :precision binary64 (/ (sin eps) (* (cos x) (cos (+ x eps)))))
double code(double x, double eps) {
	return sin(eps) / (cos(x) * cos((x + eps)));
}
real(8) function code(x, eps)
    real(8), intent (in) :: x
    real(8), intent (in) :: eps
    code = sin(eps) / (cos(x) * cos((x + eps)))
end function
public static double code(double x, double eps) {
	return Math.sin(eps) / (Math.cos(x) * Math.cos((x + eps)));
}
def code(x, eps):
	return math.sin(eps) / (math.cos(x) * math.cos((x + eps)))
function code(x, eps)
	return Float64(sin(eps) / Float64(cos(x) * cos(Float64(x + eps))))
end
function tmp = code(x, eps)
	tmp = sin(eps) / (cos(x) * cos((x + eps)));
end
code[x_, eps_] := N[(N[Sin[eps], $MachinePrecision] / N[(N[Cos[x], $MachinePrecision] * N[Cos[N[(x + eps), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\sin \varepsilon}{\cos x \cdot \cos \left(x + \varepsilon\right)}
\end{array}

Reproduce

?
herbie shell --seed 2024067 
(FPCore (x eps)
  :name "2tan (problem 3.3.2)"
  :precision binary64
  :pre (and (and (and (<= -10000.0 x) (<= x 10000.0)) (< (* 1e-16 (fabs x)) eps)) (< eps (fabs x)))

  :alt
  (/ (sin eps) (* (cos x) (cos (+ x eps))))

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