2cbrt (problem 3.3.4)

Percentage Accurate: 9.2% → 99.1%
Time: 28.3s
Alternatives: 9
Speedup: 2.0×

Specification

?
\[x > 1 \land x < 10^{+308}\]
\[\begin{array}{l} \\ \sqrt[3]{x + 1} - \sqrt[3]{x} \end{array} \]
(FPCore (x) :precision binary64 (- (cbrt (+ x 1.0)) (cbrt x)))
double code(double x) {
	return cbrt((x + 1.0)) - cbrt(x);
}
public static double code(double x) {
	return Math.cbrt((x + 1.0)) - Math.cbrt(x);
}
function code(x)
	return Float64(cbrt(Float64(x + 1.0)) - cbrt(x))
end
code[x_] := N[(N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision] - N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\sqrt[3]{x + 1} - \sqrt[3]{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 9 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: 9.2% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \sqrt[3]{x + 1} - \sqrt[3]{x} \end{array} \]
(FPCore (x) :precision binary64 (- (cbrt (+ x 1.0)) (cbrt x)))
double code(double x) {
	return cbrt((x + 1.0)) - cbrt(x);
}
public static double code(double x) {
	return Math.cbrt((x + 1.0)) - Math.cbrt(x);
}
function code(x)
	return Float64(cbrt(Float64(x + 1.0)) - cbrt(x))
end
code[x_] := N[(N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision] - N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\sqrt[3]{x + 1} - \sqrt[3]{x}
\end{array}

Alternative 1: 99.1% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \frac{1}{\left(\sqrt[3]{{x}^{2}} + \sqrt[3]{x \cdot \left(1 + x\right)}\right) + {\left(\sqrt[3]{1 + x}\right)}^{2}} \end{array} \]
(FPCore (x)
 :precision binary64
 (/
  1.0
  (+
   (+ (cbrt (pow x 2.0)) (cbrt (* x (+ 1.0 x))))
   (pow (cbrt (+ 1.0 x)) 2.0))))
double code(double x) {
	return 1.0 / ((cbrt(pow(x, 2.0)) + cbrt((x * (1.0 + x)))) + pow(cbrt((1.0 + x)), 2.0));
}
public static double code(double x) {
	return 1.0 / ((Math.cbrt(Math.pow(x, 2.0)) + Math.cbrt((x * (1.0 + x)))) + Math.pow(Math.cbrt((1.0 + x)), 2.0));
}
function code(x)
	return Float64(1.0 / Float64(Float64(cbrt((x ^ 2.0)) + cbrt(Float64(x * Float64(1.0 + x)))) + (cbrt(Float64(1.0 + x)) ^ 2.0)))
end
code[x_] := N[(1.0 / N[(N[(N[Power[N[Power[x, 2.0], $MachinePrecision], 1/3], $MachinePrecision] + N[Power[N[(x * N[(1.0 + x), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision] + N[Power[N[Power[N[(1.0 + x), $MachinePrecision], 1/3], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{\left(\sqrt[3]{{x}^{2}} + \sqrt[3]{x \cdot \left(1 + x\right)}\right) + {\left(\sqrt[3]{1 + x}\right)}^{2}}
\end{array}
Derivation
  1. Initial program 7.5%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-exp-log7.5%

      \[\leadsto \color{blue}{e^{\log \left(\sqrt[3]{x + 1} - \sqrt[3]{x}\right)}} \]
  4. Applied egg-rr7.5%

    \[\leadsto \color{blue}{e^{\log \left(\sqrt[3]{x + 1} - \sqrt[3]{x}\right)}} \]
  5. Step-by-step derivation
    1. rem-exp-log7.5%

      \[\leadsto \color{blue}{\sqrt[3]{x + 1} - \sqrt[3]{x}} \]
    2. flip3--7.5%

      \[\leadsto \color{blue}{\frac{{\left(\sqrt[3]{x + 1}\right)}^{3} - {\left(\sqrt[3]{x}\right)}^{3}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)}} \]
    3. +-commutative7.5%

      \[\leadsto \frac{{\left(\sqrt[3]{\color{blue}{1 + x}}\right)}^{3} - {\left(\sqrt[3]{x}\right)}^{3}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
    4. +-commutative7.5%

      \[\leadsto \frac{{\left(\sqrt[3]{\color{blue}{x + 1}}\right)}^{3} - {\left(\sqrt[3]{x}\right)}^{3}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
    5. rem-cube-cbrt7.7%

      \[\leadsto \frac{\color{blue}{\left(x + 1\right)} - {\left(\sqrt[3]{x}\right)}^{3}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
    6. rem-cube-cbrt11.1%

      \[\leadsto \frac{\left(x + 1\right) - \color{blue}{x}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
    7. div-sub7.9%

      \[\leadsto \color{blue}{\frac{x + 1}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} - \frac{x}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)}} \]
  6. Applied egg-rr7.8%

    \[\leadsto \color{blue}{\frac{1 + x}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{1 + x}\right)} - \frac{x}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{1 + x}\right)}} \]
  7. Step-by-step derivation
    1. div-sub11.1%

      \[\leadsto \color{blue}{\frac{\left(1 + x\right) - x}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{1 + x}\right)}} \]
    2. associate--l+98.4%

      \[\leadsto \frac{\color{blue}{1 + \left(x - x\right)}}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{1 + x}\right)} \]
    3. +-inverses98.4%

      \[\leadsto \frac{1 + \color{blue}{0}}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{1 + x}\right)} \]
    4. metadata-eval98.4%

      \[\leadsto \frac{\color{blue}{1}}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{1 + x}\right)} \]
    5. +-commutative98.4%

      \[\leadsto \frac{1}{\color{blue}{\sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{1 + x}\right) + {\left(\sqrt[3]{1 + x}\right)}^{2}}} \]
    6. fma-define98.4%

      \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{1 + x}, {\left(\sqrt[3]{1 + x}\right)}^{2}\right)}} \]
    7. +-commutative98.4%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{\color{blue}{x + 1}}, {\left(\sqrt[3]{1 + x}\right)}^{2}\right)} \]
    8. +-commutative98.4%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{x + 1}, {\left(\sqrt[3]{\color{blue}{x + 1}}\right)}^{2}\right)} \]
  8. Simplified98.4%

    \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{x + 1}, {\left(\sqrt[3]{x + 1}\right)}^{2}\right)}} \]
  9. Step-by-step derivation
    1. fma-undefine98.4%

      \[\leadsto \frac{1}{\color{blue}{\sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{x + 1}\right) + {\left(\sqrt[3]{x + 1}\right)}^{2}}} \]
    2. +-commutative98.4%

      \[\leadsto \frac{1}{\color{blue}{{\left(\sqrt[3]{x + 1}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{x + 1}\right)}} \]
    3. distribute-rgt-in98.4%

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x + 1}\right)}^{2} + \color{blue}{\left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)}} \]
    4. associate-+r+98.4%

      \[\leadsto \frac{1}{\color{blue}{\left({\left(\sqrt[3]{x + 1}\right)}^{2} + \sqrt[3]{x} \cdot \sqrt[3]{x}\right) + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}}} \]
    5. pow298.4%

      \[\leadsto \frac{1}{\left({\left(\sqrt[3]{x + 1}\right)}^{2} + \color{blue}{{\left(\sqrt[3]{x}\right)}^{2}}\right) + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}} \]
    6. cbrt-unprod98.8%

      \[\leadsto \frac{1}{\left({\left(\sqrt[3]{x + 1}\right)}^{2} + {\left(\sqrt[3]{x}\right)}^{2}\right) + \color{blue}{\sqrt[3]{\left(x + 1\right) \cdot x}}} \]
  10. Applied egg-rr98.8%

    \[\leadsto \frac{1}{\color{blue}{\left({\left(\sqrt[3]{x + 1}\right)}^{2} + {\left(\sqrt[3]{x}\right)}^{2}\right) + \sqrt[3]{\left(x + 1\right) \cdot x}}} \]
  11. Step-by-step derivation
    1. associate-+l+98.7%

      \[\leadsto \frac{1}{\color{blue}{{\left(\sqrt[3]{x + 1}\right)}^{2} + \left({\left(\sqrt[3]{x}\right)}^{2} + \sqrt[3]{\left(x + 1\right) \cdot x}\right)}} \]
    2. +-commutative98.7%

      \[\leadsto \frac{1}{{\left(\sqrt[3]{\color{blue}{1 + x}}\right)}^{2} + \left({\left(\sqrt[3]{x}\right)}^{2} + \sqrt[3]{\left(x + 1\right) \cdot x}\right)} \]
    3. *-commutative98.7%

      \[\leadsto \frac{1}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \left({\left(\sqrt[3]{x}\right)}^{2} + \sqrt[3]{\color{blue}{x \cdot \left(x + 1\right)}}\right)} \]
    4. +-commutative98.7%

      \[\leadsto \frac{1}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \left({\left(\sqrt[3]{x}\right)}^{2} + \sqrt[3]{x \cdot \color{blue}{\left(1 + x\right)}}\right)} \]
  12. Simplified98.7%

    \[\leadsto \frac{1}{\color{blue}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \left({\left(\sqrt[3]{x}\right)}^{2} + \sqrt[3]{x \cdot \left(1 + x\right)}\right)}} \]
  13. Taylor expanded in x around 0 99.0%

    \[\leadsto \frac{1}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \left(\color{blue}{\sqrt[3]{{x}^{2}}} + \sqrt[3]{x \cdot \left(1 + x\right)}\right)} \]
  14. Final simplification99.0%

    \[\leadsto \frac{1}{\left(\sqrt[3]{{x}^{2}} + \sqrt[3]{x \cdot \left(1 + x\right)}\right) + {\left(\sqrt[3]{1 + x}\right)}^{2}} \]
  15. Add Preprocessing

Alternative 2: 98.5% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt[3]{1 + x}\\ \frac{1}{{t\_0}^{2} + \sqrt[3]{x} \cdot \left(t\_0 + \sqrt[3]{x}\right)} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (cbrt (+ 1.0 x))))
   (/ 1.0 (+ (pow t_0 2.0) (* (cbrt x) (+ t_0 (cbrt x)))))))
double code(double x) {
	double t_0 = cbrt((1.0 + x));
	return 1.0 / (pow(t_0, 2.0) + (cbrt(x) * (t_0 + cbrt(x))));
}
public static double code(double x) {
	double t_0 = Math.cbrt((1.0 + x));
	return 1.0 / (Math.pow(t_0, 2.0) + (Math.cbrt(x) * (t_0 + Math.cbrt(x))));
}
function code(x)
	t_0 = cbrt(Float64(1.0 + x))
	return Float64(1.0 / Float64((t_0 ^ 2.0) + Float64(cbrt(x) * Float64(t_0 + cbrt(x)))))
end
code[x_] := Block[{t$95$0 = N[Power[N[(1.0 + x), $MachinePrecision], 1/3], $MachinePrecision]}, N[(1.0 / N[(N[Power[t$95$0, 2.0], $MachinePrecision] + N[(N[Power[x, 1/3], $MachinePrecision] * N[(t$95$0 + N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sqrt[3]{1 + x}\\
\frac{1}{{t\_0}^{2} + \sqrt[3]{x} \cdot \left(t\_0 + \sqrt[3]{x}\right)}
\end{array}
\end{array}
Derivation
  1. Initial program 7.5%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-exp-log7.5%

      \[\leadsto \color{blue}{e^{\log \left(\sqrt[3]{x + 1} - \sqrt[3]{x}\right)}} \]
  4. Applied egg-rr7.5%

    \[\leadsto \color{blue}{e^{\log \left(\sqrt[3]{x + 1} - \sqrt[3]{x}\right)}} \]
  5. Step-by-step derivation
    1. rem-exp-log7.5%

      \[\leadsto \color{blue}{\sqrt[3]{x + 1} - \sqrt[3]{x}} \]
    2. flip3--7.5%

      \[\leadsto \color{blue}{\frac{{\left(\sqrt[3]{x + 1}\right)}^{3} - {\left(\sqrt[3]{x}\right)}^{3}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)}} \]
    3. +-commutative7.5%

      \[\leadsto \frac{{\left(\sqrt[3]{\color{blue}{1 + x}}\right)}^{3} - {\left(\sqrt[3]{x}\right)}^{3}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
    4. +-commutative7.5%

      \[\leadsto \frac{{\left(\sqrt[3]{\color{blue}{x + 1}}\right)}^{3} - {\left(\sqrt[3]{x}\right)}^{3}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
    5. rem-cube-cbrt7.7%

      \[\leadsto \frac{\color{blue}{\left(x + 1\right)} - {\left(\sqrt[3]{x}\right)}^{3}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
    6. rem-cube-cbrt11.1%

      \[\leadsto \frac{\left(x + 1\right) - \color{blue}{x}}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} \]
    7. div-sub7.9%

      \[\leadsto \color{blue}{\frac{x + 1}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)} - \frac{x}{\sqrt[3]{x + 1} \cdot \sqrt[3]{x + 1} + \left(\sqrt[3]{x} \cdot \sqrt[3]{x} + \sqrt[3]{x + 1} \cdot \sqrt[3]{x}\right)}} \]
  6. Applied egg-rr7.8%

    \[\leadsto \color{blue}{\frac{1 + x}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{1 + x}\right)} - \frac{x}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{1 + x}\right)}} \]
  7. Step-by-step derivation
    1. div-sub11.1%

      \[\leadsto \color{blue}{\frac{\left(1 + x\right) - x}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{1 + x}\right)}} \]
    2. associate--l+98.4%

      \[\leadsto \frac{\color{blue}{1 + \left(x - x\right)}}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{1 + x}\right)} \]
    3. +-inverses98.4%

      \[\leadsto \frac{1 + \color{blue}{0}}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{1 + x}\right)} \]
    4. metadata-eval98.4%

      \[\leadsto \frac{\color{blue}{1}}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{1 + x}\right)} \]
    5. +-commutative98.4%

      \[\leadsto \frac{1}{\color{blue}{\sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{1 + x}\right) + {\left(\sqrt[3]{1 + x}\right)}^{2}}} \]
    6. fma-define98.4%

      \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{1 + x}, {\left(\sqrt[3]{1 + x}\right)}^{2}\right)}} \]
    7. +-commutative98.4%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{\color{blue}{x + 1}}, {\left(\sqrt[3]{1 + x}\right)}^{2}\right)} \]
    8. +-commutative98.4%

      \[\leadsto \frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{x + 1}, {\left(\sqrt[3]{\color{blue}{x + 1}}\right)}^{2}\right)} \]
  8. Simplified98.4%

    \[\leadsto \color{blue}{\frac{1}{\mathsf{fma}\left(\sqrt[3]{x}, \sqrt[3]{x} + \sqrt[3]{x + 1}, {\left(\sqrt[3]{x + 1}\right)}^{2}\right)}} \]
  9. Step-by-step derivation
    1. fma-undefine98.4%

      \[\leadsto \frac{1}{\color{blue}{\sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{x + 1}\right) + {\left(\sqrt[3]{x + 1}\right)}^{2}}} \]
    2. +-commutative98.4%

      \[\leadsto \frac{1}{\color{blue}{{\left(\sqrt[3]{x + 1}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x} + \sqrt[3]{x + 1}\right)}} \]
    3. +-commutative98.4%

      \[\leadsto \frac{1}{{\left(\sqrt[3]{x + 1}\right)}^{2} + \sqrt[3]{x} \cdot \color{blue}{\left(\sqrt[3]{x + 1} + \sqrt[3]{x}\right)}} \]
  10. Applied egg-rr98.4%

    \[\leadsto \frac{1}{\color{blue}{{\left(\sqrt[3]{x + 1}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{x + 1} + \sqrt[3]{x}\right)}} \]
  11. Final simplification98.4%

    \[\leadsto \frac{1}{{\left(\sqrt[3]{1 + x}\right)}^{2} + \sqrt[3]{x} \cdot \left(\sqrt[3]{1 + x} + \sqrt[3]{x}\right)} \]
  12. Add Preprocessing

Alternative 3: 97.2% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \frac{\sqrt[3]{\frac{1}{{x}^{2}}} \cdot -0.1111111111111111 + \sqrt[3]{x} \cdot 0.3333333333333333}{x} \end{array} \]
(FPCore (x)
 :precision binary64
 (/
  (+
   (* (cbrt (/ 1.0 (pow x 2.0))) -0.1111111111111111)
   (* (cbrt x) 0.3333333333333333))
  x))
double code(double x) {
	return ((cbrt((1.0 / pow(x, 2.0))) * -0.1111111111111111) + (cbrt(x) * 0.3333333333333333)) / x;
}
public static double code(double x) {
	return ((Math.cbrt((1.0 / Math.pow(x, 2.0))) * -0.1111111111111111) + (Math.cbrt(x) * 0.3333333333333333)) / x;
}
function code(x)
	return Float64(Float64(Float64(cbrt(Float64(1.0 / (x ^ 2.0))) * -0.1111111111111111) + Float64(cbrt(x) * 0.3333333333333333)) / x)
end
code[x_] := N[(N[(N[(N[Power[N[(1.0 / N[Power[x, 2.0], $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision] * -0.1111111111111111), $MachinePrecision] + N[(N[Power[x, 1/3], $MachinePrecision] * 0.3333333333333333), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]
\begin{array}{l}

\\
\frac{\sqrt[3]{\frac{1}{{x}^{2}}} \cdot -0.1111111111111111 + \sqrt[3]{x} \cdot 0.3333333333333333}{x}
\end{array}
Derivation
  1. Initial program 7.5%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-sqr-sqrt7.8%

      \[\leadsto \color{blue}{\sqrt{\sqrt[3]{x + 1}} \cdot \sqrt{\sqrt[3]{x + 1}}} - \sqrt[3]{x} \]
    2. add-sqr-sqrt7.3%

      \[\leadsto \sqrt{\sqrt[3]{x + 1}} \cdot \sqrt{\sqrt[3]{x + 1}} - \color{blue}{\sqrt{\sqrt[3]{x}} \cdot \sqrt{\sqrt[3]{x}}} \]
    3. difference-of-squares7.4%

      \[\leadsto \color{blue}{\left(\sqrt{\sqrt[3]{x + 1}} + \sqrt{\sqrt[3]{x}}\right) \cdot \left(\sqrt{\sqrt[3]{x + 1}} - \sqrt{\sqrt[3]{x}}\right)} \]
    4. pow1/37.4%

      \[\leadsto \left(\sqrt{\color{blue}{{\left(x + 1\right)}^{0.3333333333333333}}} + \sqrt{\sqrt[3]{x}}\right) \cdot \left(\sqrt{\sqrt[3]{x + 1}} - \sqrt{\sqrt[3]{x}}\right) \]
    5. sqrt-pow17.4%

      \[\leadsto \left(\color{blue}{{\left(x + 1\right)}^{\left(\frac{0.3333333333333333}{2}\right)}} + \sqrt{\sqrt[3]{x}}\right) \cdot \left(\sqrt{\sqrt[3]{x + 1}} - \sqrt{\sqrt[3]{x}}\right) \]
    6. metadata-eval7.4%

      \[\leadsto \left({\left(x + 1\right)}^{\color{blue}{0.16666666666666666}} + \sqrt{\sqrt[3]{x}}\right) \cdot \left(\sqrt{\sqrt[3]{x + 1}} - \sqrt{\sqrt[3]{x}}\right) \]
    7. pow1/37.4%

      \[\leadsto \left({\left(x + 1\right)}^{0.16666666666666666} + \sqrt{\color{blue}{{x}^{0.3333333333333333}}}\right) \cdot \left(\sqrt{\sqrt[3]{x + 1}} - \sqrt{\sqrt[3]{x}}\right) \]
    8. sqrt-pow17.4%

      \[\leadsto \left({\left(x + 1\right)}^{0.16666666666666666} + \color{blue}{{x}^{\left(\frac{0.3333333333333333}{2}\right)}}\right) \cdot \left(\sqrt{\sqrt[3]{x + 1}} - \sqrt{\sqrt[3]{x}}\right) \]
    9. metadata-eval7.4%

      \[\leadsto \left({\left(x + 1\right)}^{0.16666666666666666} + {x}^{\color{blue}{0.16666666666666666}}\right) \cdot \left(\sqrt{\sqrt[3]{x + 1}} - \sqrt{\sqrt[3]{x}}\right) \]
    10. pow1/35.3%

      \[\leadsto \left({\left(x + 1\right)}^{0.16666666666666666} + {x}^{0.16666666666666666}\right) \cdot \left(\sqrt{\color{blue}{{\left(x + 1\right)}^{0.3333333333333333}}} - \sqrt{\sqrt[3]{x}}\right) \]
    11. sqrt-pow15.3%

      \[\leadsto \left({\left(x + 1\right)}^{0.16666666666666666} + {x}^{0.16666666666666666}\right) \cdot \left(\color{blue}{{\left(x + 1\right)}^{\left(\frac{0.3333333333333333}{2}\right)}} - \sqrt{\sqrt[3]{x}}\right) \]
    12. metadata-eval5.3%

      \[\leadsto \left({\left(x + 1\right)}^{0.16666666666666666} + {x}^{0.16666666666666666}\right) \cdot \left({\left(x + 1\right)}^{\color{blue}{0.16666666666666666}} - \sqrt{\sqrt[3]{x}}\right) \]
    13. pow1/37.5%

      \[\leadsto \left({\left(x + 1\right)}^{0.16666666666666666} + {x}^{0.16666666666666666}\right) \cdot \left({\left(x + 1\right)}^{0.16666666666666666} - \sqrt{\color{blue}{{x}^{0.3333333333333333}}}\right) \]
    14. sqrt-pow17.4%

      \[\leadsto \left({\left(x + 1\right)}^{0.16666666666666666} + {x}^{0.16666666666666666}\right) \cdot \left({\left(x + 1\right)}^{0.16666666666666666} - \color{blue}{{x}^{\left(\frac{0.3333333333333333}{2}\right)}}\right) \]
    15. metadata-eval7.4%

      \[\leadsto \left({\left(x + 1\right)}^{0.16666666666666666} + {x}^{0.16666666666666666}\right) \cdot \left({\left(x + 1\right)}^{0.16666666666666666} - {x}^{\color{blue}{0.16666666666666666}}\right) \]
  4. Applied egg-rr7.4%

    \[\leadsto \color{blue}{\left({\left(x + 1\right)}^{0.16666666666666666} + {x}^{0.16666666666666666}\right) \cdot \left({\left(x + 1\right)}^{0.16666666666666666} - {x}^{0.16666666666666666}\right)} \]
  5. Taylor expanded in x around inf 97.7%

    \[\leadsto \color{blue}{\frac{-0.1388888888888889 \cdot \sqrt[3]{\frac{1}{{x}^{2}}} + \left(0.027777777777777776 \cdot \sqrt[3]{\frac{1}{{x}^{2}}} + 0.3333333333333333 \cdot \sqrt[3]{x}\right)}{x}} \]
  6. Step-by-step derivation
    1. associate-+r+97.7%

      \[\leadsto \frac{\color{blue}{\left(-0.1388888888888889 \cdot \sqrt[3]{\frac{1}{{x}^{2}}} + 0.027777777777777776 \cdot \sqrt[3]{\frac{1}{{x}^{2}}}\right) + 0.3333333333333333 \cdot \sqrt[3]{x}}}{x} \]
    2. distribute-rgt-out97.7%

      \[\leadsto \frac{\color{blue}{\sqrt[3]{\frac{1}{{x}^{2}}} \cdot \left(-0.1388888888888889 + 0.027777777777777776\right)} + 0.3333333333333333 \cdot \sqrt[3]{x}}{x} \]
    3. metadata-eval97.7%

      \[\leadsto \frac{\sqrt[3]{\frac{1}{{x}^{2}}} \cdot \color{blue}{-0.1111111111111111} + 0.3333333333333333 \cdot \sqrt[3]{x}}{x} \]
  7. Simplified97.7%

    \[\leadsto \color{blue}{\frac{\sqrt[3]{\frac{1}{{x}^{2}}} \cdot -0.1111111111111111 + 0.3333333333333333 \cdot \sqrt[3]{x}}{x}} \]
  8. Final simplification97.7%

    \[\leadsto \frac{\sqrt[3]{\frac{1}{{x}^{2}}} \cdot -0.1111111111111111 + \sqrt[3]{x} \cdot 0.3333333333333333}{x} \]
  9. Add Preprocessing

Alternative 4: 95.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ 0.3333333333333333 \cdot \frac{1}{\sqrt[3]{{x}^{2}}} \end{array} \]
(FPCore (x)
 :precision binary64
 (* 0.3333333333333333 (/ 1.0 (cbrt (pow x 2.0)))))
double code(double x) {
	return 0.3333333333333333 * (1.0 / cbrt(pow(x, 2.0)));
}
public static double code(double x) {
	return 0.3333333333333333 * (1.0 / Math.cbrt(Math.pow(x, 2.0)));
}
function code(x)
	return Float64(0.3333333333333333 * Float64(1.0 / cbrt((x ^ 2.0))))
end
code[x_] := N[(0.3333333333333333 * N[(1.0 / N[Power[N[Power[x, 2.0], $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.3333333333333333 \cdot \frac{1}{\sqrt[3]{{x}^{2}}}
\end{array}
Derivation
  1. Initial program 7.5%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf 96.2%

    \[\leadsto \color{blue}{0.3333333333333333 \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
  4. Step-by-step derivation
    1. cbrt-div96.5%

      \[\leadsto 0.3333333333333333 \cdot \color{blue}{\frac{\sqrt[3]{1}}{\sqrt[3]{{x}^{2}}}} \]
    2. metadata-eval96.5%

      \[\leadsto 0.3333333333333333 \cdot \frac{\color{blue}{1}}{\sqrt[3]{{x}^{2}}} \]
  5. Applied egg-rr96.5%

    \[\leadsto 0.3333333333333333 \cdot \color{blue}{\frac{1}{\sqrt[3]{{x}^{2}}}} \]
  6. Final simplification96.5%

    \[\leadsto 0.3333333333333333 \cdot \frac{1}{\sqrt[3]{{x}^{2}}} \]
  7. Add Preprocessing

Alternative 5: 94.8% accurate, 1.0× speedup?

\[\begin{array}{l} \\ 0.3333333333333333 \cdot \sqrt[3]{{x}^{-2}} \end{array} \]
(FPCore (x) :precision binary64 (* 0.3333333333333333 (cbrt (pow x -2.0))))
double code(double x) {
	return 0.3333333333333333 * cbrt(pow(x, -2.0));
}
public static double code(double x) {
	return 0.3333333333333333 * Math.cbrt(Math.pow(x, -2.0));
}
function code(x)
	return Float64(0.3333333333333333 * cbrt((x ^ -2.0)))
end
code[x_] := N[(0.3333333333333333 * N[Power[N[Power[x, -2.0], $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.3333333333333333 \cdot \sqrt[3]{{x}^{-2}}
\end{array}
Derivation
  1. Initial program 7.5%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-exp-log7.5%

      \[\leadsto \color{blue}{e^{\log \left(\sqrt[3]{x + 1} - \sqrt[3]{x}\right)}} \]
  4. Applied egg-rr7.5%

    \[\leadsto \color{blue}{e^{\log \left(\sqrt[3]{x + 1} - \sqrt[3]{x}\right)}} \]
  5. Taylor expanded in x around inf 96.2%

    \[\leadsto \color{blue}{0.3333333333333333 \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
  6. Step-by-step derivation
    1. *-commutative96.2%

      \[\leadsto \color{blue}{\sqrt[3]{\frac{1}{{x}^{2}}} \cdot 0.3333333333333333} \]
    2. exp-to-pow90.9%

      \[\leadsto \sqrt[3]{\frac{1}{\color{blue}{e^{\log x \cdot 2}}}} \cdot 0.3333333333333333 \]
    3. *-commutative90.9%

      \[\leadsto \sqrt[3]{\frac{1}{e^{\color{blue}{2 \cdot \log x}}}} \cdot 0.3333333333333333 \]
    4. rec-exp90.9%

      \[\leadsto \sqrt[3]{\color{blue}{e^{-2 \cdot \log x}}} \cdot 0.3333333333333333 \]
    5. mul-1-neg90.9%

      \[\leadsto \sqrt[3]{e^{\color{blue}{-1 \cdot \left(2 \cdot \log x\right)}}} \cdot 0.3333333333333333 \]
    6. associate-*r*90.9%

      \[\leadsto \sqrt[3]{e^{\color{blue}{\left(-1 \cdot 2\right) \cdot \log x}}} \cdot 0.3333333333333333 \]
    7. metadata-eval90.9%

      \[\leadsto \sqrt[3]{e^{\color{blue}{-2} \cdot \log x}} \cdot 0.3333333333333333 \]
    8. *-commutative90.9%

      \[\leadsto \sqrt[3]{e^{\color{blue}{\log x \cdot -2}}} \cdot 0.3333333333333333 \]
    9. exp-to-pow96.2%

      \[\leadsto \sqrt[3]{\color{blue}{{x}^{-2}}} \cdot 0.3333333333333333 \]
  7. Simplified96.2%

    \[\leadsto \color{blue}{\sqrt[3]{{x}^{-2}} \cdot 0.3333333333333333} \]
  8. Final simplification96.2%

    \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{{x}^{-2}} \]
  9. Add Preprocessing

Alternative 6: 95.1% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{0.3333333333333333}{\sqrt[3]{{x}^{2}}} \end{array} \]
(FPCore (x) :precision binary64 (/ 0.3333333333333333 (cbrt (pow x 2.0))))
double code(double x) {
	return 0.3333333333333333 / cbrt(pow(x, 2.0));
}
public static double code(double x) {
	return 0.3333333333333333 / Math.cbrt(Math.pow(x, 2.0));
}
function code(x)
	return Float64(0.3333333333333333 / cbrt((x ^ 2.0)))
end
code[x_] := N[(0.3333333333333333 / N[Power[N[Power[x, 2.0], $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{0.3333333333333333}{\sqrt[3]{{x}^{2}}}
\end{array}
Derivation
  1. Initial program 7.5%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf 96.2%

    \[\leadsto \color{blue}{0.3333333333333333 \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
  4. Step-by-step derivation
    1. cbrt-div96.5%

      \[\leadsto 0.3333333333333333 \cdot \color{blue}{\frac{\sqrt[3]{1}}{\sqrt[3]{{x}^{2}}}} \]
    2. metadata-eval96.5%

      \[\leadsto 0.3333333333333333 \cdot \frac{\color{blue}{1}}{\sqrt[3]{{x}^{2}}} \]
    3. unpow296.5%

      \[\leadsto 0.3333333333333333 \cdot \frac{1}{\sqrt[3]{\color{blue}{x \cdot x}}} \]
    4. cbrt-prod95.8%

      \[\leadsto 0.3333333333333333 \cdot \frac{1}{\color{blue}{\sqrt[3]{x} \cdot \sqrt[3]{x}}} \]
    5. un-div-inv95.8%

      \[\leadsto \color{blue}{\frac{0.3333333333333333}{\sqrt[3]{x} \cdot \sqrt[3]{x}}} \]
    6. cbrt-prod96.5%

      \[\leadsto \frac{0.3333333333333333}{\color{blue}{\sqrt[3]{x \cdot x}}} \]
    7. unpow296.5%

      \[\leadsto \frac{0.3333333333333333}{\sqrt[3]{\color{blue}{{x}^{2}}}} \]
  5. Applied egg-rr96.5%

    \[\leadsto \color{blue}{\frac{0.3333333333333333}{\sqrt[3]{{x}^{2}}}} \]
  6. Final simplification96.5%

    \[\leadsto \frac{0.3333333333333333}{\sqrt[3]{{x}^{2}}} \]
  7. Add Preprocessing

Alternative 7: 94.8% accurate, 1.9× speedup?

\[\begin{array}{l} \\ 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{x} \cdot \frac{1}{x}} \end{array} \]
(FPCore (x)
 :precision binary64
 (* 0.3333333333333333 (cbrt (* (/ 1.0 x) (/ 1.0 x)))))
double code(double x) {
	return 0.3333333333333333 * cbrt(((1.0 / x) * (1.0 / x)));
}
public static double code(double x) {
	return 0.3333333333333333 * Math.cbrt(((1.0 / x) * (1.0 / x)));
}
function code(x)
	return Float64(0.3333333333333333 * cbrt(Float64(Float64(1.0 / x) * Float64(1.0 / x))))
end
code[x_] := N[(0.3333333333333333 * N[Power[N[(N[(1.0 / x), $MachinePrecision] * N[(1.0 / x), $MachinePrecision]), $MachinePrecision], 1/3], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.3333333333333333 \cdot \sqrt[3]{\frac{1}{x} \cdot \frac{1}{x}}
\end{array}
Derivation
  1. Initial program 7.5%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf 96.2%

    \[\leadsto \color{blue}{0.3333333333333333 \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
  4. Step-by-step derivation
    1. add-sqr-sqrt96.2%

      \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\color{blue}{\sqrt{\frac{1}{{x}^{2}}} \cdot \sqrt{\frac{1}{{x}^{2}}}}} \]
    2. sqrt-div96.2%

      \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\color{blue}{\frac{\sqrt{1}}{\sqrt{{x}^{2}}}} \cdot \sqrt{\frac{1}{{x}^{2}}}} \]
    3. metadata-eval96.2%

      \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{\color{blue}{1}}{\sqrt{{x}^{2}}} \cdot \sqrt{\frac{1}{{x}^{2}}}} \]
    4. sqrt-pow196.2%

      \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{\color{blue}{{x}^{\left(\frac{2}{2}\right)}}} \cdot \sqrt{\frac{1}{{x}^{2}}}} \]
    5. metadata-eval96.2%

      \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{{x}^{\color{blue}{1}}} \cdot \sqrt{\frac{1}{{x}^{2}}}} \]
    6. pow196.2%

      \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{\color{blue}{x}} \cdot \sqrt{\frac{1}{{x}^{2}}}} \]
    7. sqrt-div96.2%

      \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{x} \cdot \color{blue}{\frac{\sqrt{1}}{\sqrt{{x}^{2}}}}} \]
    8. metadata-eval96.2%

      \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{x} \cdot \frac{\color{blue}{1}}{\sqrt{{x}^{2}}}} \]
    9. sqrt-pow196.2%

      \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{x} \cdot \frac{1}{\color{blue}{{x}^{\left(\frac{2}{2}\right)}}}} \]
    10. metadata-eval96.2%

      \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{x} \cdot \frac{1}{{x}^{\color{blue}{1}}}} \]
    11. pow196.2%

      \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{x} \cdot \frac{1}{\color{blue}{x}}} \]
  5. Applied egg-rr96.2%

    \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\color{blue}{\frac{1}{x} \cdot \frac{1}{x}}} \]
  6. Final simplification96.2%

    \[\leadsto 0.3333333333333333 \cdot \sqrt[3]{\frac{1}{x} \cdot \frac{1}{x}} \]
  7. Add Preprocessing

Alternative 8: 88.5% accurate, 2.0× speedup?

\[\begin{array}{l} \\ 0.3333333333333333 \cdot {x}^{-0.6666666666666666} \end{array} \]
(FPCore (x)
 :precision binary64
 (* 0.3333333333333333 (pow x -0.6666666666666666)))
double code(double x) {
	return 0.3333333333333333 * pow(x, -0.6666666666666666);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 0.3333333333333333d0 * (x ** (-0.6666666666666666d0))
end function
public static double code(double x) {
	return 0.3333333333333333 * Math.pow(x, -0.6666666666666666);
}
def code(x):
	return 0.3333333333333333 * math.pow(x, -0.6666666666666666)
function code(x)
	return Float64(0.3333333333333333 * (x ^ -0.6666666666666666))
end
function tmp = code(x)
	tmp = 0.3333333333333333 * (x ^ -0.6666666666666666);
end
code[x_] := N[(0.3333333333333333 * N[Power[x, -0.6666666666666666], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.3333333333333333 \cdot {x}^{-0.6666666666666666}
\end{array}
Derivation
  1. Initial program 7.5%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around inf 96.2%

    \[\leadsto \color{blue}{0.3333333333333333 \cdot \sqrt[3]{\frac{1}{{x}^{2}}}} \]
  4. Step-by-step derivation
    1. pow1/389.6%

      \[\leadsto 0.3333333333333333 \cdot \color{blue}{{\left(\frac{1}{{x}^{2}}\right)}^{0.3333333333333333}} \]
    2. pow-flip89.6%

      \[\leadsto 0.3333333333333333 \cdot {\color{blue}{\left({x}^{\left(-2\right)}\right)}}^{0.3333333333333333} \]
    3. pow-pow89.6%

      \[\leadsto 0.3333333333333333 \cdot \color{blue}{{x}^{\left(\left(-2\right) \cdot 0.3333333333333333\right)}} \]
    4. metadata-eval89.6%

      \[\leadsto 0.3333333333333333 \cdot {x}^{\left(\color{blue}{-2} \cdot 0.3333333333333333\right)} \]
    5. metadata-eval89.6%

      \[\leadsto 0.3333333333333333 \cdot {x}^{\color{blue}{-0.6666666666666666}} \]
  5. Applied egg-rr89.6%

    \[\leadsto 0.3333333333333333 \cdot \color{blue}{{x}^{-0.6666666666666666}} \]
  6. Final simplification89.6%

    \[\leadsto 0.3333333333333333 \cdot {x}^{-0.6666666666666666} \]
  7. Add Preprocessing

Alternative 9: 6.9% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \sqrt[3]{x} \end{array} \]
(FPCore (x) :precision binary64 (cbrt x))
double code(double x) {
	return cbrt(x);
}
public static double code(double x) {
	return Math.cbrt(x);
}
function code(x)
	return cbrt(x)
end
code[x_] := N[Power[x, 1/3], $MachinePrecision]
\begin{array}{l}

\\
\sqrt[3]{x}
\end{array}
Derivation
  1. Initial program 7.5%

    \[\sqrt[3]{x + 1} - \sqrt[3]{x} \]
  2. Add Preprocessing
  3. Taylor expanded in x around 0 1.7%

    \[\leadsto \color{blue}{1 - \sqrt[3]{x}} \]
  4. Step-by-step derivation
    1. sub-neg1.7%

      \[\leadsto \color{blue}{1 + \left(-\sqrt[3]{x}\right)} \]
    2. rem-square-sqrt0.0%

      \[\leadsto 1 + \color{blue}{\sqrt{-\sqrt[3]{x}} \cdot \sqrt{-\sqrt[3]{x}}} \]
    3. fabs-sqr0.0%

      \[\leadsto 1 + \color{blue}{\left|\sqrt{-\sqrt[3]{x}} \cdot \sqrt{-\sqrt[3]{x}}\right|} \]
    4. rem-square-sqrt6.8%

      \[\leadsto 1 + \left|\color{blue}{-\sqrt[3]{x}}\right| \]
    5. fabs-neg6.8%

      \[\leadsto 1 + \color{blue}{\left|\sqrt[3]{x}\right|} \]
    6. unpow1/36.8%

      \[\leadsto 1 + \left|\color{blue}{{x}^{0.3333333333333333}}\right| \]
    7. metadata-eval6.8%

      \[\leadsto 1 + \left|{x}^{\color{blue}{\left(2 \cdot 0.16666666666666666\right)}}\right| \]
    8. pow-sqr6.8%

      \[\leadsto 1 + \left|\color{blue}{{x}^{0.16666666666666666} \cdot {x}^{0.16666666666666666}}\right| \]
    9. fabs-sqr6.8%

      \[\leadsto 1 + \color{blue}{{x}^{0.16666666666666666} \cdot {x}^{0.16666666666666666}} \]
    10. pow-sqr6.8%

      \[\leadsto 1 + \color{blue}{{x}^{\left(2 \cdot 0.16666666666666666\right)}} \]
    11. metadata-eval6.8%

      \[\leadsto 1 + {x}^{\color{blue}{0.3333333333333333}} \]
    12. unpow1/36.8%

      \[\leadsto 1 + \color{blue}{\sqrt[3]{x}} \]
  5. Simplified6.8%

    \[\leadsto \color{blue}{1 + \sqrt[3]{x}} \]
  6. Taylor expanded in x around inf 6.8%

    \[\leadsto \color{blue}{\sqrt[3]{x}} \]
  7. Final simplification6.8%

    \[\leadsto \sqrt[3]{x} \]
  8. Add Preprocessing

Developer target: 98.5% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \sqrt[3]{x + 1}\\ \frac{1}{\left(t\_0 \cdot t\_0 + \sqrt[3]{x} \cdot t\_0\right) + \sqrt[3]{x} \cdot \sqrt[3]{x}} \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (cbrt (+ x 1.0))))
   (/ 1.0 (+ (+ (* t_0 t_0) (* (cbrt x) t_0)) (* (cbrt x) (cbrt x))))))
double code(double x) {
	double t_0 = cbrt((x + 1.0));
	return 1.0 / (((t_0 * t_0) + (cbrt(x) * t_0)) + (cbrt(x) * cbrt(x)));
}
public static double code(double x) {
	double t_0 = Math.cbrt((x + 1.0));
	return 1.0 / (((t_0 * t_0) + (Math.cbrt(x) * t_0)) + (Math.cbrt(x) * Math.cbrt(x)));
}
function code(x)
	t_0 = cbrt(Float64(x + 1.0))
	return Float64(1.0 / Float64(Float64(Float64(t_0 * t_0) + Float64(cbrt(x) * t_0)) + Float64(cbrt(x) * cbrt(x))))
end
code[x_] := Block[{t$95$0 = N[Power[N[(x + 1.0), $MachinePrecision], 1/3], $MachinePrecision]}, N[(1.0 / N[(N[(N[(t$95$0 * t$95$0), $MachinePrecision] + N[(N[Power[x, 1/3], $MachinePrecision] * t$95$0), $MachinePrecision]), $MachinePrecision] + N[(N[Power[x, 1/3], $MachinePrecision] * N[Power[x, 1/3], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \sqrt[3]{x + 1}\\
\frac{1}{\left(t\_0 \cdot t\_0 + \sqrt[3]{x} \cdot t\_0\right) + \sqrt[3]{x} \cdot \sqrt[3]{x}}
\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2024083 
(FPCore (x)
  :name "2cbrt (problem 3.3.4)"
  :precision binary64
  :pre (and (> x 1.0) (< x 1e+308))

  :alt
  (/ 1.0 (+ (+ (* (cbrt (+ x 1.0)) (cbrt (+ x 1.0))) (* (cbrt x) (cbrt (+ x 1.0)))) (* (cbrt x) (cbrt x))))

  (- (cbrt (+ x 1.0)) (cbrt x)))