Cubic critical, medium range

Percentage Accurate: 31.3% → 95.3%
Time: 15.1s
Alternatives: 7
Speedup: 23.2×

Specification

?
\[\left(\left(1.1102230246251565 \cdot 10^{-16} < a \land a < 9007199254740992\right) \land \left(1.1102230246251565 \cdot 10^{-16} < b \land b < 9007199254740992\right)\right) \land \left(1.1102230246251565 \cdot 10^{-16} < c \land c < 9007199254740992\right)\]
\[\begin{array}{l} \\ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))
double code(double a, double b, double c) {
	return (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = (-b + sqrt(((b * b) - ((3.0d0 * a) * c)))) / (3.0d0 * a)
end function
public static double code(double a, double b, double c) {
	return (-b + Math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
def code(a, b, c):
	return (-b + math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a)
function code(a, b, c)
	return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a))
end
function tmp = code(a, b, c)
	tmp = (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(3.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a}
\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 7 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: 31.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))
double code(double a, double b, double c) {
	return (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = (-b + sqrt(((b * b) - ((3.0d0 * a) * c)))) / (3.0d0 * a)
end function
public static double code(double a, double b, double c) {
	return (-b + Math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
}
def code(a, b, c):
	return (-b + math.sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a)
function code(a, b, c)
	return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(3.0 * a) * c)))) / Float64(3.0 * a))
end
function tmp = code(a, b, c)
	tmp = (-b + sqrt(((b * b) - ((3.0 * a) * c)))) / (3.0 * a);
end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(3.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a}
\end{array}

Alternative 1: 95.3% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := b \cdot \left(b \cdot b\right)\\ \frac{c \cdot -0.5 + \left(\frac{\left(c \cdot c\right) \cdot \left(\frac{-0.5625 \cdot \left(c \cdot \left(a \cdot a\right)\right)}{b \cdot b} + a \cdot -0.375\right)}{b \cdot b} + \left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(\left(c \cdot \left(c \cdot \left(c \cdot c\right)\right)\right) \cdot \frac{-1.0546875}{a \cdot \left(t\_0 \cdot t\_0\right)}\right)\right)}{b} \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (let* ((t_0 (* b (* b b))))
   (/
    (+
     (* c -0.5)
     (+
      (/
       (* (* c c) (+ (/ (* -0.5625 (* c (* a a))) (* b b)) (* a -0.375)))
       (* b b))
      (*
       (* a (* a (* a a)))
       (* (* c (* c (* c c))) (/ -1.0546875 (* a (* t_0 t_0)))))))
    b)))
double code(double a, double b, double c) {
	double t_0 = b * (b * b);
	return ((c * -0.5) + ((((c * c) * (((-0.5625 * (c * (a * a))) / (b * b)) + (a * -0.375))) / (b * b)) + ((a * (a * (a * a))) * ((c * (c * (c * c))) * (-1.0546875 / (a * (t_0 * t_0))))))) / b;
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    real(8) :: t_0
    t_0 = b * (b * b)
    code = ((c * (-0.5d0)) + ((((c * c) * ((((-0.5625d0) * (c * (a * a))) / (b * b)) + (a * (-0.375d0)))) / (b * b)) + ((a * (a * (a * a))) * ((c * (c * (c * c))) * ((-1.0546875d0) / (a * (t_0 * t_0))))))) / b
end function
public static double code(double a, double b, double c) {
	double t_0 = b * (b * b);
	return ((c * -0.5) + ((((c * c) * (((-0.5625 * (c * (a * a))) / (b * b)) + (a * -0.375))) / (b * b)) + ((a * (a * (a * a))) * ((c * (c * (c * c))) * (-1.0546875 / (a * (t_0 * t_0))))))) / b;
}
def code(a, b, c):
	t_0 = b * (b * b)
	return ((c * -0.5) + ((((c * c) * (((-0.5625 * (c * (a * a))) / (b * b)) + (a * -0.375))) / (b * b)) + ((a * (a * (a * a))) * ((c * (c * (c * c))) * (-1.0546875 / (a * (t_0 * t_0))))))) / b
function code(a, b, c)
	t_0 = Float64(b * Float64(b * b))
	return Float64(Float64(Float64(c * -0.5) + Float64(Float64(Float64(Float64(c * c) * Float64(Float64(Float64(-0.5625 * Float64(c * Float64(a * a))) / Float64(b * b)) + Float64(a * -0.375))) / Float64(b * b)) + Float64(Float64(a * Float64(a * Float64(a * a))) * Float64(Float64(c * Float64(c * Float64(c * c))) * Float64(-1.0546875 / Float64(a * Float64(t_0 * t_0))))))) / b)
end
function tmp = code(a, b, c)
	t_0 = b * (b * b);
	tmp = ((c * -0.5) + ((((c * c) * (((-0.5625 * (c * (a * a))) / (b * b)) + (a * -0.375))) / (b * b)) + ((a * (a * (a * a))) * ((c * (c * (c * c))) * (-1.0546875 / (a * (t_0 * t_0))))))) / b;
end
code[a_, b_, c_] := Block[{t$95$0 = N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[(c * -0.5), $MachinePrecision] + N[(N[(N[(N[(c * c), $MachinePrecision] * N[(N[(N[(-0.5625 * N[(c * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(a * -0.375), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(N[(a * N[(a * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(N[(c * N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(-1.0546875 / N[(a * N[(t$95$0 * t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := b \cdot \left(b \cdot b\right)\\
\frac{c \cdot -0.5 + \left(\frac{\left(c \cdot c\right) \cdot \left(\frac{-0.5625 \cdot \left(c \cdot \left(a \cdot a\right)\right)}{b \cdot b} + a \cdot -0.375\right)}{b \cdot b} + \left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(\left(c \cdot \left(c \cdot \left(c \cdot c\right)\right)\right) \cdot \frac{-1.0546875}{a \cdot \left(t\_0 \cdot t\_0\right)}\right)\right)}{b}
\end{array}
\end{array}
Derivation
  1. Initial program 30.0%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in b around inf

    \[\leadsto \color{blue}{\frac{\frac{-9}{16} \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} + \left(\frac{-1}{2} \cdot c + \left(\frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}} + \frac{-1}{6} \cdot \frac{\frac{81}{64} \cdot \left({a}^{4} \cdot {c}^{4}\right) + \frac{81}{16} \cdot \left({a}^{4} \cdot {c}^{4}\right)}{a \cdot {b}^{6}}\right)\right)}{b}} \]
  4. Simplified95.3%

    \[\leadsto \color{blue}{\frac{\left(\left(c \cdot -0.5 + a \cdot \left(-0.375 \cdot \left(c \cdot \frac{c}{b \cdot b}\right)\right)\right) + \frac{-0.5625 \cdot \left(c \cdot \left(c \cdot \left(c \cdot \left(a \cdot a\right)\right)\right)\right)}{\left(b \cdot b\right) \cdot \left(b \cdot b\right)}\right) + \left(\left({a}^{4} \cdot {c}^{4}\right) \cdot \frac{6.328125}{{b}^{6}}\right) \cdot \frac{-0.16666666666666666}{a}}{b}} \]
  5. Applied egg-rr95.3%

    \[\leadsto \color{blue}{\frac{c \cdot -0.5 + \left(\left(\frac{c}{\frac{b \cdot b}{c}} \cdot \left(a \cdot -0.375\right) + \frac{\left(c \cdot \left(c \cdot \left(a \cdot a\right)\right)\right) \cdot \left(c \cdot -0.5625\right)}{b \cdot \left(b \cdot \left(b \cdot b\right)\right)}\right) + \left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(\left(c \cdot \left(c \cdot \left(c \cdot c\right)\right)\right) \cdot \frac{-1.0546875}{\left(\left(b \cdot \left(b \cdot b\right)\right) \cdot \left(b \cdot \left(b \cdot b\right)\right)\right) \cdot a}\right)\right)}{b}} \]
  6. Taylor expanded in b around inf

    \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\color{blue}{\left(\frac{\frac{-9}{16} \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{2}} + \frac{-3}{8} \cdot \left(a \cdot {c}^{2}\right)}{{b}^{2}}\right)}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
  7. Step-by-step derivation
    1. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\left(\frac{-9}{16} \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{2}} + \frac{-3}{8} \cdot \left(a \cdot {c}^{2}\right)\right), \left({b}^{2}\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
  8. Simplified95.3%

    \[\leadsto \frac{c \cdot -0.5 + \left(\color{blue}{\frac{\frac{\left(c \cdot \left(c \cdot c\right)\right) \cdot \left(\left(a \cdot a\right) \cdot -0.5625\right)}{b \cdot b} + -0.375 \cdot \left(a \cdot \left(c \cdot c\right)\right)}{b \cdot b}} + \left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(\left(c \cdot \left(c \cdot \left(c \cdot c\right)\right)\right) \cdot \frac{-1.0546875}{\left(\left(b \cdot \left(b \cdot b\right)\right) \cdot \left(b \cdot \left(b \cdot b\right)\right)\right) \cdot a}\right)\right)}{b} \]
  9. Taylor expanded in c around 0

    \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\color{blue}{\left({c}^{2} \cdot \left(\frac{-9}{16} \cdot \frac{{a}^{2} \cdot c}{{b}^{2}} + \frac{-3}{8} \cdot a\right)\right)}, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
  10. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\left({c}^{2}\right), \left(\frac{-9}{16} \cdot \frac{{a}^{2} \cdot c}{{b}^{2}} + \frac{-3}{8} \cdot a\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
    2. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\left(c \cdot c\right), \left(\frac{-9}{16} \cdot \frac{{a}^{2} \cdot c}{{b}^{2}} + \frac{-3}{8} \cdot a\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(c, c\right), \left(\frac{-9}{16} \cdot \frac{{a}^{2} \cdot c}{{b}^{2}} + \frac{-3}{8} \cdot a\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
    4. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(c, c\right), \mathsf{+.f64}\left(\left(\frac{-9}{16} \cdot \frac{{a}^{2} \cdot c}{{b}^{2}}\right), \left(\frac{-3}{8} \cdot a\right)\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
    5. associate-*r/N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(c, c\right), \mathsf{+.f64}\left(\left(\frac{\frac{-9}{16} \cdot \left({a}^{2} \cdot c\right)}{{b}^{2}}\right), \left(\frac{-3}{8} \cdot a\right)\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
    6. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(c, c\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\left(\frac{-9}{16} \cdot \left({a}^{2} \cdot c\right)\right), \left({b}^{2}\right)\right), \left(\frac{-3}{8} \cdot a\right)\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
    7. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(c, c\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, \left({a}^{2} \cdot c\right)\right), \left({b}^{2}\right)\right), \left(\frac{-3}{8} \cdot a\right)\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
    8. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(c, c\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, \left(c \cdot {a}^{2}\right)\right), \left({b}^{2}\right)\right), \left(\frac{-3}{8} \cdot a\right)\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
    9. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(c, c\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, \mathsf{*.f64}\left(c, \left({a}^{2}\right)\right)\right), \left({b}^{2}\right)\right), \left(\frac{-3}{8} \cdot a\right)\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
    10. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(c, c\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, \mathsf{*.f64}\left(c, \left(a \cdot a\right)\right)\right), \left({b}^{2}\right)\right), \left(\frac{-3}{8} \cdot a\right)\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
    11. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(c, c\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(a, a\right)\right)\right), \left({b}^{2}\right)\right), \left(\frac{-3}{8} \cdot a\right)\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
    12. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(c, c\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(a, a\right)\right)\right), \left(b \cdot b\right)\right), \left(\frac{-3}{8} \cdot a\right)\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
    13. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(c, c\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \left(\frac{-3}{8} \cdot a\right)\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
    14. *-lowering-*.f6495.3%

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(c, c\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\frac{-3}{8}, a\right)\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
  11. Simplified95.3%

    \[\leadsto \frac{c \cdot -0.5 + \left(\frac{\color{blue}{\left(c \cdot c\right) \cdot \left(\frac{-0.5625 \cdot \left(c \cdot \left(a \cdot a\right)\right)}{b \cdot b} + -0.375 \cdot a\right)}}{b \cdot b} + \left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(\left(c \cdot \left(c \cdot \left(c \cdot c\right)\right)\right) \cdot \frac{-1.0546875}{\left(\left(b \cdot \left(b \cdot b\right)\right) \cdot \left(b \cdot \left(b \cdot b\right)\right)\right) \cdot a}\right)\right)}{b} \]
  12. Final simplification95.3%

    \[\leadsto \frac{c \cdot -0.5 + \left(\frac{\left(c \cdot c\right) \cdot \left(\frac{-0.5625 \cdot \left(c \cdot \left(a \cdot a\right)\right)}{b \cdot b} + a \cdot -0.375\right)}{b \cdot b} + \left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(\left(c \cdot \left(c \cdot \left(c \cdot c\right)\right)\right) \cdot \frac{-1.0546875}{a \cdot \left(\left(b \cdot \left(b \cdot b\right)\right) \cdot \left(b \cdot \left(b \cdot b\right)\right)\right)}\right)\right)}{b} \]
  13. Add Preprocessing

Alternative 2: 93.8% accurate, 3.5× speedup?

\[\begin{array}{l} \\ \frac{c \cdot -0.5 + \frac{\frac{\left(c \cdot \left(c \cdot c\right)\right) \cdot \left(-0.5625 \cdot \left(a \cdot a\right)\right)}{b \cdot b} + -0.375 \cdot \left(\left(c \cdot c\right) \cdot a\right)}{b \cdot b}}{b} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/
  (+
   (* c -0.5)
   (/
    (+
     (/ (* (* c (* c c)) (* -0.5625 (* a a))) (* b b))
     (* -0.375 (* (* c c) a)))
    (* b b)))
  b))
double code(double a, double b, double c) {
	return ((c * -0.5) + (((((c * (c * c)) * (-0.5625 * (a * a))) / (b * b)) + (-0.375 * ((c * c) * a))) / (b * b))) / b;
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = ((c * (-0.5d0)) + (((((c * (c * c)) * ((-0.5625d0) * (a * a))) / (b * b)) + ((-0.375d0) * ((c * c) * a))) / (b * b))) / b
end function
public static double code(double a, double b, double c) {
	return ((c * -0.5) + (((((c * (c * c)) * (-0.5625 * (a * a))) / (b * b)) + (-0.375 * ((c * c) * a))) / (b * b))) / b;
}
def code(a, b, c):
	return ((c * -0.5) + (((((c * (c * c)) * (-0.5625 * (a * a))) / (b * b)) + (-0.375 * ((c * c) * a))) / (b * b))) / b
function code(a, b, c)
	return Float64(Float64(Float64(c * -0.5) + Float64(Float64(Float64(Float64(Float64(c * Float64(c * c)) * Float64(-0.5625 * Float64(a * a))) / Float64(b * b)) + Float64(-0.375 * Float64(Float64(c * c) * a))) / Float64(b * b))) / b)
end
function tmp = code(a, b, c)
	tmp = ((c * -0.5) + (((((c * (c * c)) * (-0.5625 * (a * a))) / (b * b)) + (-0.375 * ((c * c) * a))) / (b * b))) / b;
end
code[a_, b_, c_] := N[(N[(N[(c * -0.5), $MachinePrecision] + N[(N[(N[(N[(N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision] * N[(-0.5625 * N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision] + N[(-0.375 * N[(N[(c * c), $MachinePrecision] * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}

\\
\frac{c \cdot -0.5 + \frac{\frac{\left(c \cdot \left(c \cdot c\right)\right) \cdot \left(-0.5625 \cdot \left(a \cdot a\right)\right)}{b \cdot b} + -0.375 \cdot \left(\left(c \cdot c\right) \cdot a\right)}{b \cdot b}}{b}
\end{array}
Derivation
  1. Initial program 30.0%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in b around inf

    \[\leadsto \color{blue}{\frac{\frac{-9}{16} \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} + \left(\frac{-1}{2} \cdot c + \left(\frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}} + \frac{-1}{6} \cdot \frac{\frac{81}{64} \cdot \left({a}^{4} \cdot {c}^{4}\right) + \frac{81}{16} \cdot \left({a}^{4} \cdot {c}^{4}\right)}{a \cdot {b}^{6}}\right)\right)}{b}} \]
  4. Simplified95.3%

    \[\leadsto \color{blue}{\frac{\left(\left(c \cdot -0.5 + a \cdot \left(-0.375 \cdot \left(c \cdot \frac{c}{b \cdot b}\right)\right)\right) + \frac{-0.5625 \cdot \left(c \cdot \left(c \cdot \left(c \cdot \left(a \cdot a\right)\right)\right)\right)}{\left(b \cdot b\right) \cdot \left(b \cdot b\right)}\right) + \left(\left({a}^{4} \cdot {c}^{4}\right) \cdot \frac{6.328125}{{b}^{6}}\right) \cdot \frac{-0.16666666666666666}{a}}{b}} \]
  5. Applied egg-rr95.3%

    \[\leadsto \color{blue}{\frac{c \cdot -0.5 + \left(\left(\frac{c}{\frac{b \cdot b}{c}} \cdot \left(a \cdot -0.375\right) + \frac{\left(c \cdot \left(c \cdot \left(a \cdot a\right)\right)\right) \cdot \left(c \cdot -0.5625\right)}{b \cdot \left(b \cdot \left(b \cdot b\right)\right)}\right) + \left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(\left(c \cdot \left(c \cdot \left(c \cdot c\right)\right)\right) \cdot \frac{-1.0546875}{\left(\left(b \cdot \left(b \cdot b\right)\right) \cdot \left(b \cdot \left(b \cdot b\right)\right)\right) \cdot a}\right)\right)}{b}} \]
  6. Taylor expanded in b around inf

    \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \color{blue}{\left(\frac{\frac{-9}{16} \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{2}} + \frac{-3}{8} \cdot \left(a \cdot {c}^{2}\right)}{{b}^{2}}\right)}\right), b\right) \]
  7. Step-by-step derivation
    1. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{/.f64}\left(\left(\frac{-9}{16} \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{2}} + \frac{-3}{8} \cdot \left(a \cdot {c}^{2}\right)\right), \left({b}^{2}\right)\right)\right), b\right) \]
  8. Simplified93.8%

    \[\leadsto \frac{c \cdot -0.5 + \color{blue}{\frac{\frac{\left(c \cdot \left(c \cdot c\right)\right) \cdot \left(\left(a \cdot a\right) \cdot -0.5625\right)}{b \cdot b} + -0.375 \cdot \left(a \cdot \left(c \cdot c\right)\right)}{b \cdot b}}}{b} \]
  9. Final simplification93.8%

    \[\leadsto \frac{c \cdot -0.5 + \frac{\frac{\left(c \cdot \left(c \cdot c\right)\right) \cdot \left(-0.5625 \cdot \left(a \cdot a\right)\right)}{b \cdot b} + -0.375 \cdot \left(\left(c \cdot c\right) \cdot a\right)}{b \cdot b}}{b} \]
  10. Add Preprocessing

Alternative 3: 93.8% accurate, 3.5× speedup?

\[\begin{array}{l} \\ \frac{c \cdot -0.5}{b} + a \cdot \frac{\left(-0.5625 \cdot a\right) \cdot \frac{c \cdot \left(c \cdot c\right)}{b \cdot b} + \left(c \cdot c\right) \cdot -0.375}{b \cdot \left(b \cdot b\right)} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (+
  (/ (* c -0.5) b)
  (*
   a
   (/
    (+ (* (* -0.5625 a) (/ (* c (* c c)) (* b b))) (* (* c c) -0.375))
    (* b (* b b))))))
double code(double a, double b, double c) {
	return ((c * -0.5) / b) + (a * ((((-0.5625 * a) * ((c * (c * c)) / (b * b))) + ((c * c) * -0.375)) / (b * (b * b))));
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = ((c * (-0.5d0)) / b) + (a * (((((-0.5625d0) * a) * ((c * (c * c)) / (b * b))) + ((c * c) * (-0.375d0))) / (b * (b * b))))
end function
public static double code(double a, double b, double c) {
	return ((c * -0.5) / b) + (a * ((((-0.5625 * a) * ((c * (c * c)) / (b * b))) + ((c * c) * -0.375)) / (b * (b * b))));
}
def code(a, b, c):
	return ((c * -0.5) / b) + (a * ((((-0.5625 * a) * ((c * (c * c)) / (b * b))) + ((c * c) * -0.375)) / (b * (b * b))))
function code(a, b, c)
	return Float64(Float64(Float64(c * -0.5) / b) + Float64(a * Float64(Float64(Float64(Float64(-0.5625 * a) * Float64(Float64(c * Float64(c * c)) / Float64(b * b))) + Float64(Float64(c * c) * -0.375)) / Float64(b * Float64(b * b)))))
end
function tmp = code(a, b, c)
	tmp = ((c * -0.5) / b) + (a * ((((-0.5625 * a) * ((c * (c * c)) / (b * b))) + ((c * c) * -0.375)) / (b * (b * b))));
end
code[a_, b_, c_] := N[(N[(N[(c * -0.5), $MachinePrecision] / b), $MachinePrecision] + N[(a * N[(N[(N[(N[(-0.5625 * a), $MachinePrecision] * N[(N[(c * N[(c * c), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(c * c), $MachinePrecision] * -0.375), $MachinePrecision]), $MachinePrecision] / N[(b * N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{c \cdot -0.5}{b} + a \cdot \frac{\left(-0.5625 \cdot a\right) \cdot \frac{c \cdot \left(c \cdot c\right)}{b \cdot b} + \left(c \cdot c\right) \cdot -0.375}{b \cdot \left(b \cdot b\right)}
\end{array}
Derivation
  1. Initial program 30.0%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in a around 0

    \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{c}{b} + a \cdot \left(\frac{-9}{16} \cdot \frac{a \cdot {c}^{3}}{{b}^{5}} + \frac{-3}{8} \cdot \frac{{c}^{2}}{{b}^{3}}\right)} \]
  4. Simplified93.7%

    \[\leadsto \color{blue}{\frac{c \cdot -0.5}{b} + a \cdot \left(\frac{-0.375 \cdot \left(c \cdot \frac{c}{b \cdot b}\right)}{b} + \frac{\left(\left(c \cdot \left(c \cdot c\right)\right) \cdot -0.5625\right) \cdot a}{{b}^{5}}\right)} \]
  5. Taylor expanded in b around inf

    \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \color{blue}{\left(\frac{\frac{-9}{16} \cdot \frac{a \cdot {c}^{3}}{{b}^{2}} + \frac{-3}{8} \cdot {c}^{2}}{{b}^{3}}\right)}\right)\right) \]
  6. Step-by-step derivation
    1. /-lowering-/.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\left(\frac{-9}{16} \cdot \frac{a \cdot {c}^{3}}{{b}^{2}} + \frac{-3}{8} \cdot {c}^{2}\right), \color{blue}{\left({b}^{3}\right)}\right)\right)\right) \]
    2. +-lowering-+.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\left(\frac{-9}{16} \cdot \frac{a \cdot {c}^{3}}{{b}^{2}}\right), \left(\frac{-3}{8} \cdot {c}^{2}\right)\right), \left({\color{blue}{b}}^{3}\right)\right)\right)\right) \]
    3. associate-/l*N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\left(\frac{-9}{16} \cdot \left(a \cdot \frac{{c}^{3}}{{b}^{2}}\right)\right), \left(\frac{-3}{8} \cdot {c}^{2}\right)\right), \left({b}^{3}\right)\right)\right)\right) \]
    4. associate-*r*N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\left(\left(\frac{-9}{16} \cdot a\right) \cdot \frac{{c}^{3}}{{b}^{2}}\right), \left(\frac{-3}{8} \cdot {c}^{2}\right)\right), \left({b}^{3}\right)\right)\right)\right) \]
    5. *-lowering-*.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\left(\frac{-9}{16} \cdot a\right), \left(\frac{{c}^{3}}{{b}^{2}}\right)\right), \left(\frac{-3}{8} \cdot {c}^{2}\right)\right), \left({b}^{3}\right)\right)\right)\right) \]
    6. *-lowering-*.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \left(\frac{{c}^{3}}{{b}^{2}}\right)\right), \left(\frac{-3}{8} \cdot {c}^{2}\right)\right), \left({b}^{3}\right)\right)\right)\right) \]
    7. /-lowering-/.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\left({c}^{3}\right), \left({b}^{2}\right)\right)\right), \left(\frac{-3}{8} \cdot {c}^{2}\right)\right), \left({b}^{3}\right)\right)\right)\right) \]
    8. cube-multN/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\left(c \cdot \left(c \cdot c\right)\right), \left({b}^{2}\right)\right)\right), \left(\frac{-3}{8} \cdot {c}^{2}\right)\right), \left({b}^{3}\right)\right)\right)\right) \]
    9. unpow2N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\left(c \cdot {c}^{2}\right), \left({b}^{2}\right)\right)\right), \left(\frac{-3}{8} \cdot {c}^{2}\right)\right), \left({b}^{3}\right)\right)\right)\right) \]
    10. *-lowering-*.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \left({c}^{2}\right)\right), \left({b}^{2}\right)\right)\right), \left(\frac{-3}{8} \cdot {c}^{2}\right)\right), \left({b}^{3}\right)\right)\right)\right) \]
    11. unpow2N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \left(c \cdot c\right)\right), \left({b}^{2}\right)\right)\right), \left(\frac{-3}{8} \cdot {c}^{2}\right)\right), \left({b}^{3}\right)\right)\right)\right) \]
    12. *-lowering-*.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right), \left({b}^{2}\right)\right)\right), \left(\frac{-3}{8} \cdot {c}^{2}\right)\right), \left({b}^{3}\right)\right)\right)\right) \]
    13. unpow2N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right), \left(b \cdot b\right)\right)\right), \left(\frac{-3}{8} \cdot {c}^{2}\right)\right), \left({b}^{3}\right)\right)\right)\right) \]
    14. *-lowering-*.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right), \mathsf{*.f64}\left(b, b\right)\right)\right), \left(\frac{-3}{8} \cdot {c}^{2}\right)\right), \left({b}^{3}\right)\right)\right)\right) \]
    15. *-lowering-*.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right), \mathsf{*.f64}\left(b, b\right)\right)\right), \mathsf{*.f64}\left(\frac{-3}{8}, \left({c}^{2}\right)\right)\right), \left({b}^{3}\right)\right)\right)\right) \]
    16. unpow2N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right), \mathsf{*.f64}\left(b, b\right)\right)\right), \mathsf{*.f64}\left(\frac{-3}{8}, \left(c \cdot c\right)\right)\right), \left({b}^{3}\right)\right)\right)\right) \]
    17. *-lowering-*.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right), \mathsf{*.f64}\left(b, b\right)\right)\right), \mathsf{*.f64}\left(\frac{-3}{8}, \mathsf{*.f64}\left(c, c\right)\right)\right), \left({b}^{3}\right)\right)\right)\right) \]
    18. cube-multN/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right), \mathsf{*.f64}\left(b, b\right)\right)\right), \mathsf{*.f64}\left(\frac{-3}{8}, \mathsf{*.f64}\left(c, c\right)\right)\right), \left(b \cdot \color{blue}{\left(b \cdot b\right)}\right)\right)\right)\right) \]
    19. unpow2N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right), \mathsf{*.f64}\left(b, b\right)\right)\right), \mathsf{*.f64}\left(\frac{-3}{8}, \mathsf{*.f64}\left(c, c\right)\right)\right), \left(b \cdot {b}^{\color{blue}{2}}\right)\right)\right)\right) \]
    20. *-lowering-*.f64N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right), \mathsf{*.f64}\left(b, b\right)\right)\right), \mathsf{*.f64}\left(\frac{-3}{8}, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{*.f64}\left(b, \color{blue}{\left({b}^{2}\right)}\right)\right)\right)\right) \]
    21. unpow2N/A

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right), \mathsf{*.f64}\left(b, b\right)\right)\right), \mathsf{*.f64}\left(\frac{-3}{8}, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{*.f64}\left(b, \left(b \cdot \color{blue}{b}\right)\right)\right)\right)\right) \]
    22. *-lowering-*.f6493.7%

      \[\leadsto \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right), \mathsf{*.f64}\left(a, \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(\frac{-9}{16}, a\right), \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right), \mathsf{*.f64}\left(b, b\right)\right)\right), \mathsf{*.f64}\left(\frac{-3}{8}, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, \color{blue}{b}\right)\right)\right)\right)\right) \]
  7. Simplified93.7%

    \[\leadsto \frac{c \cdot -0.5}{b} + a \cdot \color{blue}{\frac{\left(-0.5625 \cdot a\right) \cdot \frac{c \cdot \left(c \cdot c\right)}{b \cdot b} + -0.375 \cdot \left(c \cdot c\right)}{b \cdot \left(b \cdot b\right)}} \]
  8. Final simplification93.7%

    \[\leadsto \frac{c \cdot -0.5}{b} + a \cdot \frac{\left(-0.5625 \cdot a\right) \cdot \frac{c \cdot \left(c \cdot c\right)}{b \cdot b} + \left(c \cdot c\right) \cdot -0.375}{b \cdot \left(b \cdot b\right)} \]
  9. Add Preprocessing

Alternative 4: 90.7% accurate, 6.8× speedup?

\[\begin{array}{l} \\ \frac{c \cdot -0.5 + a \cdot \left(-0.375 \cdot \left(c \cdot \frac{c}{b \cdot b}\right)\right)}{b} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (+ (* c -0.5) (* a (* -0.375 (* c (/ c (* b b)))))) b))
double code(double a, double b, double c) {
	return ((c * -0.5) + (a * (-0.375 * (c * (c / (b * b)))))) / b;
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = ((c * (-0.5d0)) + (a * ((-0.375d0) * (c * (c / (b * b)))))) / b
end function
public static double code(double a, double b, double c) {
	return ((c * -0.5) + (a * (-0.375 * (c * (c / (b * b)))))) / b;
}
def code(a, b, c):
	return ((c * -0.5) + (a * (-0.375 * (c * (c / (b * b)))))) / b
function code(a, b, c)
	return Float64(Float64(Float64(c * -0.5) + Float64(a * Float64(-0.375 * Float64(c * Float64(c / Float64(b * b)))))) / b)
end
function tmp = code(a, b, c)
	tmp = ((c * -0.5) + (a * (-0.375 * (c * (c / (b * b)))))) / b;
end
code[a_, b_, c_] := N[(N[(N[(c * -0.5), $MachinePrecision] + N[(a * N[(-0.375 * N[(c * N[(c / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}

\\
\frac{c \cdot -0.5 + a \cdot \left(-0.375 \cdot \left(c \cdot \frac{c}{b \cdot b}\right)\right)}{b}
\end{array}
Derivation
  1. Initial program 30.0%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in b around inf

    \[\leadsto \color{blue}{\frac{\frac{-1}{2} \cdot c + \frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}}}{b}} \]
  4. Step-by-step derivation
    1. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\left(\frac{-1}{2} \cdot c + \frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}}\right), \color{blue}{b}\right) \]
  5. Simplified90.3%

    \[\leadsto \color{blue}{\frac{c \cdot -0.5 + a \cdot \left(-0.375 \cdot \left(c \cdot \frac{c}{b \cdot b}\right)\right)}{b}} \]
  6. Add Preprocessing

Alternative 5: 90.7% accurate, 7.7× speedup?

\[\begin{array}{l} \\ \frac{c \cdot \left(-0.5 + \frac{-0.375 \cdot \left(c \cdot a\right)}{b \cdot b}\right)}{b} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (* c (+ -0.5 (/ (* -0.375 (* c a)) (* b b)))) b))
double code(double a, double b, double c) {
	return (c * (-0.5 + ((-0.375 * (c * a)) / (b * b)))) / b;
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = (c * ((-0.5d0) + (((-0.375d0) * (c * a)) / (b * b)))) / b
end function
public static double code(double a, double b, double c) {
	return (c * (-0.5 + ((-0.375 * (c * a)) / (b * b)))) / b;
}
def code(a, b, c):
	return (c * (-0.5 + ((-0.375 * (c * a)) / (b * b)))) / b
function code(a, b, c)
	return Float64(Float64(c * Float64(-0.5 + Float64(Float64(-0.375 * Float64(c * a)) / Float64(b * b)))) / b)
end
function tmp = code(a, b, c)
	tmp = (c * (-0.5 + ((-0.375 * (c * a)) / (b * b)))) / b;
end
code[a_, b_, c_] := N[(N[(c * N[(-0.5 + N[(N[(-0.375 * N[(c * a), $MachinePrecision]), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}

\\
\frac{c \cdot \left(-0.5 + \frac{-0.375 \cdot \left(c \cdot a\right)}{b \cdot b}\right)}{b}
\end{array}
Derivation
  1. Initial program 30.0%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in b around inf

    \[\leadsto \color{blue}{\frac{\frac{-9}{16} \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{4}} + \left(\frac{-1}{2} \cdot c + \left(\frac{-3}{8} \cdot \frac{a \cdot {c}^{2}}{{b}^{2}} + \frac{-1}{6} \cdot \frac{\frac{81}{64} \cdot \left({a}^{4} \cdot {c}^{4}\right) + \frac{81}{16} \cdot \left({a}^{4} \cdot {c}^{4}\right)}{a \cdot {b}^{6}}\right)\right)}{b}} \]
  4. Simplified95.3%

    \[\leadsto \color{blue}{\frac{\left(\left(c \cdot -0.5 + a \cdot \left(-0.375 \cdot \left(c \cdot \frac{c}{b \cdot b}\right)\right)\right) + \frac{-0.5625 \cdot \left(c \cdot \left(c \cdot \left(c \cdot \left(a \cdot a\right)\right)\right)\right)}{\left(b \cdot b\right) \cdot \left(b \cdot b\right)}\right) + \left(\left({a}^{4} \cdot {c}^{4}\right) \cdot \frac{6.328125}{{b}^{6}}\right) \cdot \frac{-0.16666666666666666}{a}}{b}} \]
  5. Applied egg-rr95.3%

    \[\leadsto \color{blue}{\frac{c \cdot -0.5 + \left(\left(\frac{c}{\frac{b \cdot b}{c}} \cdot \left(a \cdot -0.375\right) + \frac{\left(c \cdot \left(c \cdot \left(a \cdot a\right)\right)\right) \cdot \left(c \cdot -0.5625\right)}{b \cdot \left(b \cdot \left(b \cdot b\right)\right)}\right) + \left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(\left(c \cdot \left(c \cdot \left(c \cdot c\right)\right)\right) \cdot \frac{-1.0546875}{\left(\left(b \cdot \left(b \cdot b\right)\right) \cdot \left(b \cdot \left(b \cdot b\right)\right)\right) \cdot a}\right)\right)}{b}} \]
  6. Taylor expanded in b around inf

    \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\color{blue}{\left(\frac{\frac{-9}{16} \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{2}} + \frac{-3}{8} \cdot \left(a \cdot {c}^{2}\right)}{{b}^{2}}\right)}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
  7. Step-by-step derivation
    1. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{+.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), \mathsf{+.f64}\left(\mathsf{/.f64}\left(\left(\frac{-9}{16} \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{2}} + \frac{-3}{8} \cdot \left(a \cdot {c}^{2}\right)\right), \left({b}^{2}\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, \mathsf{*.f64}\left(a, a\right)\right)\right), \mathsf{*.f64}\left(\mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, \mathsf{*.f64}\left(c, c\right)\right)\right), \mathsf{/.f64}\left(\frac{-135}{128}, \mathsf{*.f64}\left(\mathsf{*.f64}\left(\mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right), \mathsf{*.f64}\left(b, \mathsf{*.f64}\left(b, b\right)\right)\right), a\right)\right)\right)\right)\right)\right), b\right) \]
  8. Simplified95.3%

    \[\leadsto \frac{c \cdot -0.5 + \left(\color{blue}{\frac{\frac{\left(c \cdot \left(c \cdot c\right)\right) \cdot \left(\left(a \cdot a\right) \cdot -0.5625\right)}{b \cdot b} + -0.375 \cdot \left(a \cdot \left(c \cdot c\right)\right)}{b \cdot b}} + \left(a \cdot \left(a \cdot \left(a \cdot a\right)\right)\right) \cdot \left(\left(c \cdot \left(c \cdot \left(c \cdot c\right)\right)\right) \cdot \frac{-1.0546875}{\left(\left(b \cdot \left(b \cdot b\right)\right) \cdot \left(b \cdot \left(b \cdot b\right)\right)\right) \cdot a}\right)\right)}{b} \]
  9. Taylor expanded in c around 0

    \[\leadsto \mathsf{/.f64}\left(\color{blue}{\left(c \cdot \left(\frac{-3}{8} \cdot \frac{a \cdot c}{{b}^{2}} - \frac{1}{2}\right)\right)}, b\right) \]
  10. Step-by-step derivation
    1. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \left(\frac{-3}{8} \cdot \frac{a \cdot c}{{b}^{2}} - \frac{1}{2}\right)\right), b\right) \]
    2. sub-negN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \left(\frac{-3}{8} \cdot \frac{a \cdot c}{{b}^{2}} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right)\right), b\right) \]
    3. metadata-evalN/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \left(\frac{-3}{8} \cdot \frac{a \cdot c}{{b}^{2}} + \frac{-1}{2}\right)\right), b\right) \]
    4. +-lowering-+.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{+.f64}\left(\left(\frac{-3}{8} \cdot \frac{a \cdot c}{{b}^{2}}\right), \frac{-1}{2}\right)\right), b\right) \]
    5. associate-*r/N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{+.f64}\left(\left(\frac{\frac{-3}{8} \cdot \left(a \cdot c\right)}{{b}^{2}}\right), \frac{-1}{2}\right)\right), b\right) \]
    6. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{+.f64}\left(\mathsf{/.f64}\left(\left(\frac{-3}{8} \cdot \left(a \cdot c\right)\right), \left({b}^{2}\right)\right), \frac{-1}{2}\right)\right), b\right) \]
    7. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\frac{-3}{8}, \left(a \cdot c\right)\right), \left({b}^{2}\right)\right), \frac{-1}{2}\right)\right), b\right) \]
    8. *-lowering-*.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\frac{-3}{8}, \mathsf{*.f64}\left(a, c\right)\right), \left({b}^{2}\right)\right), \frac{-1}{2}\right)\right), b\right) \]
    9. unpow2N/A

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\frac{-3}{8}, \mathsf{*.f64}\left(a, c\right)\right), \left(b \cdot b\right)\right), \frac{-1}{2}\right)\right), b\right) \]
    10. *-lowering-*.f6490.2%

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \mathsf{+.f64}\left(\mathsf{/.f64}\left(\mathsf{*.f64}\left(\frac{-3}{8}, \mathsf{*.f64}\left(a, c\right)\right), \mathsf{*.f64}\left(b, b\right)\right), \frac{-1}{2}\right)\right), b\right) \]
  11. Simplified90.2%

    \[\leadsto \frac{\color{blue}{c \cdot \left(\frac{-0.375 \cdot \left(a \cdot c\right)}{b \cdot b} + -0.5\right)}}{b} \]
  12. Final simplification90.2%

    \[\leadsto \frac{c \cdot \left(-0.5 + \frac{-0.375 \cdot \left(c \cdot a\right)}{b \cdot b}\right)}{b} \]
  13. Add Preprocessing

Alternative 6: 81.4% accurate, 23.2× speedup?

\[\begin{array}{l} \\ \frac{c \cdot -0.5}{b} \end{array} \]
(FPCore (a b c) :precision binary64 (/ (* c -0.5) b))
double code(double a, double b, double c) {
	return (c * -0.5) / b;
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = (c * (-0.5d0)) / b
end function
public static double code(double a, double b, double c) {
	return (c * -0.5) / b;
}
def code(a, b, c):
	return (c * -0.5) / b
function code(a, b, c)
	return Float64(Float64(c * -0.5) / b)
end
function tmp = code(a, b, c)
	tmp = (c * -0.5) / b;
end
code[a_, b_, c_] := N[(N[(c * -0.5), $MachinePrecision] / b), $MachinePrecision]
\begin{array}{l}

\\
\frac{c \cdot -0.5}{b}
\end{array}
Derivation
  1. Initial program 30.0%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in b around inf

    \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{c}{b}} \]
  4. Step-by-step derivation
    1. associate-*r/N/A

      \[\leadsto \frac{\frac{-1}{2} \cdot c}{\color{blue}{b}} \]
    2. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\left(\frac{-1}{2} \cdot c\right), \color{blue}{b}\right) \]
    3. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(\left(c \cdot \frac{-1}{2}\right), b\right) \]
    4. *-lowering-*.f6481.8%

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right) \]
  5. Simplified81.8%

    \[\leadsto \color{blue}{\frac{c \cdot -0.5}{b}} \]
  6. Add Preprocessing

Alternative 7: 81.2% accurate, 23.2× speedup?

\[\begin{array}{l} \\ c \cdot \frac{-0.5}{b} \end{array} \]
(FPCore (a b c) :precision binary64 (* c (/ -0.5 b)))
double code(double a, double b, double c) {
	return c * (-0.5 / b);
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = c * ((-0.5d0) / b)
end function
public static double code(double a, double b, double c) {
	return c * (-0.5 / b);
}
def code(a, b, c):
	return c * (-0.5 / b)
function code(a, b, c)
	return Float64(c * Float64(-0.5 / b))
end
function tmp = code(a, b, c)
	tmp = c * (-0.5 / b);
end
code[a_, b_, c_] := N[(c * N[(-0.5 / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
c \cdot \frac{-0.5}{b}
\end{array}
Derivation
  1. Initial program 30.0%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in b around inf

    \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{c}{b}} \]
  4. Step-by-step derivation
    1. associate-*r/N/A

      \[\leadsto \frac{\frac{-1}{2} \cdot c}{\color{blue}{b}} \]
    2. /-lowering-/.f64N/A

      \[\leadsto \mathsf{/.f64}\left(\left(\frac{-1}{2} \cdot c\right), \color{blue}{b}\right) \]
    3. *-commutativeN/A

      \[\leadsto \mathsf{/.f64}\left(\left(c \cdot \frac{-1}{2}\right), b\right) \]
    4. *-lowering-*.f6481.8%

      \[\leadsto \mathsf{/.f64}\left(\mathsf{*.f64}\left(c, \frac{-1}{2}\right), b\right) \]
  5. Simplified81.8%

    \[\leadsto \color{blue}{\frac{c \cdot -0.5}{b}} \]
  6. Step-by-step derivation
    1. associate-/l*N/A

      \[\leadsto c \cdot \color{blue}{\frac{\frac{-1}{2}}{b}} \]
    2. *-commutativeN/A

      \[\leadsto \frac{\frac{-1}{2}}{b} \cdot \color{blue}{c} \]
    3. *-lowering-*.f64N/A

      \[\leadsto \mathsf{*.f64}\left(\left(\frac{\frac{-1}{2}}{b}\right), \color{blue}{c}\right) \]
    4. /-lowering-/.f6481.6%

      \[\leadsto \mathsf{*.f64}\left(\mathsf{/.f64}\left(\frac{-1}{2}, b\right), c\right) \]
  7. Applied egg-rr81.6%

    \[\leadsto \color{blue}{\frac{-0.5}{b} \cdot c} \]
  8. Final simplification81.6%

    \[\leadsto c \cdot \frac{-0.5}{b} \]
  9. Add Preprocessing

Reproduce

?
herbie shell --seed 2024192 
(FPCore (a b c)
  :name "Cubic critical, medium range"
  :precision binary64
  :pre (and (and (and (< 1.1102230246251565e-16 a) (< a 9007199254740992.0)) (and (< 1.1102230246251565e-16 b) (< b 9007199254740992.0))) (and (< 1.1102230246251565e-16 c) (< c 9007199254740992.0)))
  (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))