Cubic critical, narrow range

Percentage Accurate: 55.2% → 99.3%
Time: 29.8s
Alternatives: 8
Speedup: 23.2×

Specification

?
\[\left(\left(1.0536712127723509 \cdot 10^{-8} < a \land a < 94906265.62425156\right) \land \left(1.0536712127723509 \cdot 10^{-8} < b \land b < 94906265.62425156\right)\right) \land \left(1.0536712127723509 \cdot 10^{-8} < c \land c < 94906265.62425156\right)\]
\[\begin{array}{l} \\ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \end{array} \]
(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 8 alternatives:

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

Initial Program: 55.2% 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: 99.3% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \frac{\frac{c \cdot \left(3 \cdot a\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -3\right)\right)}}}{3 \cdot a} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (/ (* c (* 3.0 a)) (- (- b) (sqrt (fma b b (* c (* a -3.0)))))) (* 3.0 a)))
double code(double a, double b, double c) {
	return ((c * (3.0 * a)) / (-b - sqrt(fma(b, b, (c * (a * -3.0)))))) / (3.0 * a);
}
function code(a, b, c)
	return Float64(Float64(Float64(c * Float64(3.0 * a)) / Float64(Float64(-b) - sqrt(fma(b, b, Float64(c * Float64(a * -3.0)))))) / Float64(3.0 * a))
end
code[a_, b_, c_] := N[(N[(N[(c * N[(3.0 * a), $MachinePrecision]), $MachinePrecision] / N[((-b) - N[Sqrt[N[(b * b + N[(c * N[(a * -3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{c \cdot \left(3 \cdot a\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -3\right)\right)}}}{3 \cdot a}
\end{array}
Derivation
  1. Initial program 52.9%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-sqr-sqrt52.0%

      \[\leadsto \frac{\left(-\color{blue}{\sqrt{b} \cdot \sqrt{b}}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. distribute-rgt-neg-in52.0%

      \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  4. Applied egg-rr52.0%

    \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  5. Step-by-step derivation
    1. flip-+52.1%

      \[\leadsto \frac{\color{blue}{\frac{\left(\sqrt{b} \cdot \left(-\sqrt{b}\right)\right) \cdot \left(\sqrt{b} \cdot \left(-\sqrt{b}\right)\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}}{3 \cdot a} \]
    2. pow252.0%

      \[\leadsto \frac{\frac{\color{blue}{{\left(\sqrt{b} \cdot \left(-\sqrt{b}\right)\right)}^{2}} - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    3. distribute-rgt-neg-out52.0%

      \[\leadsto \frac{\frac{{\color{blue}{\left(-\sqrt{b} \cdot \sqrt{b}\right)}}^{2} - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    4. add-sqr-sqrt52.9%

      \[\leadsto \frac{\frac{{\left(-\color{blue}{b}\right)}^{2} - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    5. add-sqr-sqrt54.4%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \color{blue}{\left(b \cdot b - \left(3 \cdot a\right) \cdot c\right)}}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    6. pow254.4%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left(\color{blue}{{b}^{2}} - \left(3 \cdot a\right) \cdot c\right)}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    7. *-commutative54.4%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \color{blue}{c \cdot \left(3 \cdot a\right)}\right)}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    8. *-commutative54.4%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \color{blue}{\left(a \cdot 3\right)}\right)}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    9. distribute-rgt-neg-out54.4%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 3\right)\right)}{\color{blue}{\left(-\sqrt{b} \cdot \sqrt{b}\right)} - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    10. add-sqr-sqrt54.4%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 3\right)\right)}{\left(-\color{blue}{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
  6. Applied egg-rr54.4%

    \[\leadsto \frac{\color{blue}{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 3\right)\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}}{3 \cdot a} \]
  7. Step-by-step derivation
    1. associate--r-99.3%

      \[\leadsto \frac{\frac{\color{blue}{\left({\left(-b\right)}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 3\right)}}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    2. unpow299.1%

      \[\leadsto \frac{\frac{\left(\color{blue}{\left(-b\right) \cdot \left(-b\right)} - {b}^{2}\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    3. unpow299.3%

      \[\leadsto \frac{\frac{\left(\left(-b\right) \cdot \left(-b\right) - \color{blue}{b \cdot b}\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    4. difference-of-squares99.3%

      \[\leadsto \frac{\frac{\color{blue}{\left(\left(-b\right) + b\right) \cdot \left(\left(-b\right) - b\right)} + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    5. neg-mul-199.3%

      \[\leadsto \frac{\frac{\left(\color{blue}{-1 \cdot b} + b\right) \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    6. distribute-lft1-in99.3%

      \[\leadsto \frac{\frac{\color{blue}{\left(\left(-1 + 1\right) \cdot b\right)} \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    7. metadata-eval99.3%

      \[\leadsto \frac{\frac{\left(\color{blue}{0} \cdot b\right) \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    8. mul0-lft99.3%

      \[\leadsto \frac{\frac{\color{blue}{0} \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    9. unpow299.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    10. fma-neg99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\color{blue}{\mathsf{fma}\left(b, b, -c \cdot \left(a \cdot 3\right)\right)}}}}{3 \cdot a} \]
    11. associate-*r*99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(c \cdot a\right) \cdot 3}\right)}}}{3 \cdot a} \]
    12. *-commutative99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(a \cdot c\right)} \cdot 3\right)}}}{3 \cdot a} \]
    13. distribute-rgt-neg-in99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot \left(-3\right)}\right)}}}{3 \cdot a} \]
    14. metadata-eval99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot \color{blue}{-3}\right)}}}{3 \cdot a} \]
  8. Simplified99.3%

    \[\leadsto \frac{\color{blue}{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -3\right)}}}}{3 \cdot a} \]
  9. Taylor expanded in a around 0 99.3%

    \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \color{blue}{-3 \cdot \left(a \cdot c\right)}\right)}}}{3 \cdot a} \]
  10. Step-by-step derivation
    1. associate-*r*99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(-3 \cdot a\right) \cdot c}\right)}}}{3 \cdot a} \]
    2. *-commutative99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot -3\right)} \cdot c\right)}}}{3 \cdot a} \]
    3. *-commutative99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \color{blue}{c \cdot \left(a \cdot -3\right)}\right)}}}{3 \cdot a} \]
  11. Simplified99.3%

    \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \color{blue}{c \cdot \left(a \cdot -3\right)}\right)}}}{3 \cdot a} \]
  12. Taylor expanded in b around 0 99.1%

    \[\leadsto \frac{\frac{\color{blue}{3 \cdot \left(a \cdot c\right)}}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -3\right)\right)}}}{3 \cdot a} \]
  13. Step-by-step derivation
    1. *-commutative99.1%

      \[\leadsto \frac{\frac{\color{blue}{\left(a \cdot c\right) \cdot 3}}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -3\right)\right)}}}{3 \cdot a} \]
    2. *-commutative99.1%

      \[\leadsto \frac{\frac{\color{blue}{\left(c \cdot a\right)} \cdot 3}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -3\right)\right)}}}{3 \cdot a} \]
    3. associate-*r*99.3%

      \[\leadsto \frac{\frac{\color{blue}{c \cdot \left(a \cdot 3\right)}}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -3\right)\right)}}}{3 \cdot a} \]
    4. *-commutative99.3%

      \[\leadsto \frac{\frac{c \cdot \color{blue}{\left(3 \cdot a\right)}}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -3\right)\right)}}}{3 \cdot a} \]
  14. Simplified99.3%

    \[\leadsto \frac{\frac{\color{blue}{c \cdot \left(3 \cdot a\right)}}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -3\right)\right)}}}{3 \cdot a} \]
  15. Add Preprocessing

Alternative 2: 85.5% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\sqrt{b \cdot b - c \cdot \left(3 \cdot a\right)} - b}{3 \cdot a} \leq -0.095:\\ \;\;\;\;\frac{1}{\frac{3 \cdot a}{\sqrt{\mathsf{fma}\left(b, b, -3 \cdot \left(c \cdot a\right)\right)} - b}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\frac{b \cdot -2 + 1.5 \cdot \frac{c \cdot a}{b}}{c}}\\ \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (if (<= (/ (- (sqrt (- (* b b) (* c (* 3.0 a)))) b) (* 3.0 a)) -0.095)
   (/ 1.0 (/ (* 3.0 a) (- (sqrt (fma b b (* -3.0 (* c a)))) b)))
   (/ 1.0 (/ (+ (* b -2.0) (* 1.5 (/ (* c a) b))) c))))
double code(double a, double b, double c) {
	double tmp;
	if (((sqrt(((b * b) - (c * (3.0 * a)))) - b) / (3.0 * a)) <= -0.095) {
		tmp = 1.0 / ((3.0 * a) / (sqrt(fma(b, b, (-3.0 * (c * a)))) - b));
	} else {
		tmp = 1.0 / (((b * -2.0) + (1.5 * ((c * a) / b))) / c);
	}
	return tmp;
}
function code(a, b, c)
	tmp = 0.0
	if (Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(3.0 * a)))) - b) / Float64(3.0 * a)) <= -0.095)
		tmp = Float64(1.0 / Float64(Float64(3.0 * a) / Float64(sqrt(fma(b, b, Float64(-3.0 * Float64(c * a)))) - b)));
	else
		tmp = Float64(1.0 / Float64(Float64(Float64(b * -2.0) + Float64(1.5 * Float64(Float64(c * a) / b))) / c));
	end
	return tmp
end
code[a_, b_, c_] := If[LessEqual[N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(3.0 * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision], -0.095], N[(1.0 / N[(N[(3.0 * a), $MachinePrecision] / N[(N[Sqrt[N[(b * b + N[(-3.0 * N[(c * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(1.0 / N[(N[(N[(b * -2.0), $MachinePrecision] + N[(1.5 * N[(N[(c * a), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\sqrt{b \cdot b - c \cdot \left(3 \cdot a\right)} - b}{3 \cdot a} \leq -0.095:\\
\;\;\;\;\frac{1}{\frac{3 \cdot a}{\sqrt{\mathsf{fma}\left(b, b, -3 \cdot \left(c \cdot a\right)\right)} - b}}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{\frac{b \cdot -2 + 1.5 \cdot \frac{c \cdot a}{b}}{c}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 #s(literal 3 binary64) a) c)))) (*.f64 #s(literal 3 binary64) a)) < -0.095000000000000001

    1. Initial program 82.7%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. add-sqr-sqrt81.0%

        \[\leadsto \frac{\left(-\color{blue}{\sqrt{b} \cdot \sqrt{b}}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
      2. distribute-rgt-neg-in81.0%

        \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    4. Applied egg-rr81.0%

      \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    5. Step-by-step derivation
      1. clear-num81.1%

        \[\leadsto \color{blue}{\frac{1}{\frac{3 \cdot a}{\sqrt{b} \cdot \left(-\sqrt{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
      2. inv-pow81.1%

        \[\leadsto \color{blue}{{\left(\frac{3 \cdot a}{\sqrt{b} \cdot \left(-\sqrt{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1}} \]
      3. *-commutative81.1%

        \[\leadsto {\left(\frac{\color{blue}{a \cdot 3}}{\sqrt{b} \cdot \left(-\sqrt{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
      4. distribute-rgt-neg-out81.1%

        \[\leadsto {\left(\frac{a \cdot 3}{\color{blue}{\left(-\sqrt{b} \cdot \sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
      5. add-sqr-sqrt82.7%

        \[\leadsto {\left(\frac{a \cdot 3}{\left(-\color{blue}{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
      6. pow282.7%

        \[\leadsto {\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{\color{blue}{{b}^{2}} - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
      7. *-commutative82.7%

        \[\leadsto {\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - \color{blue}{c \cdot \left(3 \cdot a\right)}}}\right)}^{-1} \]
      8. *-commutative82.7%

        \[\leadsto {\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - c \cdot \color{blue}{\left(a \cdot 3\right)}}}\right)}^{-1} \]
    6. Applied egg-rr82.7%

      \[\leadsto \color{blue}{{\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}\right)}^{-1}} \]
    7. Step-by-step derivation
      1. unpow-182.7%

        \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}} \]
      2. +-commutative82.7%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\color{blue}{\sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)} + \left(-b\right)}}} \]
      3. unsub-neg82.7%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\color{blue}{\sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)} - b}}} \]
      4. unpow282.7%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\color{blue}{b \cdot b} - c \cdot \left(a \cdot 3\right)} - b}} \]
      5. fma-neg82.7%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\color{blue}{\mathsf{fma}\left(b, b, -c \cdot \left(a \cdot 3\right)\right)}} - b}} \]
      6. associate-*r*82.7%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(c \cdot a\right) \cdot 3}\right)} - b}} \]
      7. *-commutative82.7%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(a \cdot c\right)} \cdot 3\right)} - b}} \]
      8. distribute-rgt-neg-in82.7%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot \left(-3\right)}\right)} - b}} \]
      9. metadata-eval82.7%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot \color{blue}{-3}\right)} - b}} \]
    8. Simplified82.7%

      \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -3\right)} - b}}} \]

    if -0.095000000000000001 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 #s(literal 3 binary64) a) c)))) (*.f64 #s(literal 3 binary64) a))

    1. Initial program 45.1%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. add-sqr-sqrt44.5%

        \[\leadsto \frac{\left(-\color{blue}{\sqrt{b} \cdot \sqrt{b}}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
      2. distribute-rgt-neg-in44.5%

        \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    4. Applied egg-rr44.5%

      \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    5. Step-by-step derivation
      1. clear-num44.5%

        \[\leadsto \color{blue}{\frac{1}{\frac{3 \cdot a}{\sqrt{b} \cdot \left(-\sqrt{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
      2. inv-pow44.5%

        \[\leadsto \color{blue}{{\left(\frac{3 \cdot a}{\sqrt{b} \cdot \left(-\sqrt{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1}} \]
      3. *-commutative44.5%

        \[\leadsto {\left(\frac{\color{blue}{a \cdot 3}}{\sqrt{b} \cdot \left(-\sqrt{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
      4. distribute-rgt-neg-out44.5%

        \[\leadsto {\left(\frac{a \cdot 3}{\color{blue}{\left(-\sqrt{b} \cdot \sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
      5. add-sqr-sqrt45.1%

        \[\leadsto {\left(\frac{a \cdot 3}{\left(-\color{blue}{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
      6. pow245.1%

        \[\leadsto {\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{\color{blue}{{b}^{2}} - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
      7. *-commutative45.1%

        \[\leadsto {\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - \color{blue}{c \cdot \left(3 \cdot a\right)}}}\right)}^{-1} \]
      8. *-commutative45.1%

        \[\leadsto {\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - c \cdot \color{blue}{\left(a \cdot 3\right)}}}\right)}^{-1} \]
    6. Applied egg-rr45.1%

      \[\leadsto \color{blue}{{\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}\right)}^{-1}} \]
    7. Step-by-step derivation
      1. unpow-145.1%

        \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}} \]
      2. +-commutative45.1%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\color{blue}{\sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)} + \left(-b\right)}}} \]
      3. unsub-neg45.1%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\color{blue}{\sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)} - b}}} \]
      4. unpow245.1%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\color{blue}{b \cdot b} - c \cdot \left(a \cdot 3\right)} - b}} \]
      5. fma-neg45.3%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\color{blue}{\mathsf{fma}\left(b, b, -c \cdot \left(a \cdot 3\right)\right)}} - b}} \]
      6. associate-*r*45.3%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(c \cdot a\right) \cdot 3}\right)} - b}} \]
      7. *-commutative45.3%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(a \cdot c\right)} \cdot 3\right)} - b}} \]
      8. distribute-rgt-neg-in45.3%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot \left(-3\right)}\right)} - b}} \]
      9. metadata-eval45.3%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot \color{blue}{-3}\right)} - b}} \]
    8. Simplified45.3%

      \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -3\right)} - b}}} \]
    9. Taylor expanded in c around 0 89.7%

      \[\leadsto \frac{1}{\color{blue}{\frac{-2 \cdot b + 1.5 \cdot \frac{a \cdot c}{b}}{c}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification88.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\sqrt{b \cdot b - c \cdot \left(3 \cdot a\right)} - b}{3 \cdot a} \leq -0.095:\\ \;\;\;\;\frac{1}{\frac{3 \cdot a}{\sqrt{\mathsf{fma}\left(b, b, -3 \cdot \left(c \cdot a\right)\right)} - b}}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\frac{b \cdot -2 + 1.5 \cdot \frac{c \cdot a}{b}}{c}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 85.5% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\sqrt{b \cdot b - c \cdot \left(3 \cdot a\right)} - b}{3 \cdot a}\\ \mathbf{if}\;t\_0 \leq -0.095:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\frac{b \cdot -2 + 1.5 \cdot \frac{c \cdot a}{b}}{c}}\\ \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (let* ((t_0 (/ (- (sqrt (- (* b b) (* c (* 3.0 a)))) b) (* 3.0 a))))
   (if (<= t_0 -0.095)
     t_0
     (/ 1.0 (/ (+ (* b -2.0) (* 1.5 (/ (* c a) b))) c)))))
double code(double a, double b, double c) {
	double t_0 = (sqrt(((b * b) - (c * (3.0 * a)))) - b) / (3.0 * a);
	double tmp;
	if (t_0 <= -0.095) {
		tmp = t_0;
	} else {
		tmp = 1.0 / (((b * -2.0) + (1.5 * ((c * a) / b))) / c);
	}
	return tmp;
}
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
    real(8) :: tmp
    t_0 = (sqrt(((b * b) - (c * (3.0d0 * a)))) - b) / (3.0d0 * a)
    if (t_0 <= (-0.095d0)) then
        tmp = t_0
    else
        tmp = 1.0d0 / (((b * (-2.0d0)) + (1.5d0 * ((c * a) / b))) / c)
    end if
    code = tmp
end function
public static double code(double a, double b, double c) {
	double t_0 = (Math.sqrt(((b * b) - (c * (3.0 * a)))) - b) / (3.0 * a);
	double tmp;
	if (t_0 <= -0.095) {
		tmp = t_0;
	} else {
		tmp = 1.0 / (((b * -2.0) + (1.5 * ((c * a) / b))) / c);
	}
	return tmp;
}
def code(a, b, c):
	t_0 = (math.sqrt(((b * b) - (c * (3.0 * a)))) - b) / (3.0 * a)
	tmp = 0
	if t_0 <= -0.095:
		tmp = t_0
	else:
		tmp = 1.0 / (((b * -2.0) + (1.5 * ((c * a) / b))) / c)
	return tmp
function code(a, b, c)
	t_0 = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(3.0 * a)))) - b) / Float64(3.0 * a))
	tmp = 0.0
	if (t_0 <= -0.095)
		tmp = t_0;
	else
		tmp = Float64(1.0 / Float64(Float64(Float64(b * -2.0) + Float64(1.5 * Float64(Float64(c * a) / b))) / c));
	end
	return tmp
end
function tmp_2 = code(a, b, c)
	t_0 = (sqrt(((b * b) - (c * (3.0 * a)))) - b) / (3.0 * a);
	tmp = 0.0;
	if (t_0 <= -0.095)
		tmp = t_0;
	else
		tmp = 1.0 / (((b * -2.0) + (1.5 * ((c * a) / b))) / c);
	end
	tmp_2 = tmp;
end
code[a_, b_, c_] := Block[{t$95$0 = N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(3.0 * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -0.095], t$95$0, N[(1.0 / N[(N[(N[(b * -2.0), $MachinePrecision] + N[(1.5 * N[(N[(c * a), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\sqrt{b \cdot b - c \cdot \left(3 \cdot a\right)} - b}{3 \cdot a}\\
\mathbf{if}\;t\_0 \leq -0.095:\\
\;\;\;\;t\_0\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{\frac{b \cdot -2 + 1.5 \cdot \frac{c \cdot a}{b}}{c}}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 #s(literal 3 binary64) a) c)))) (*.f64 #s(literal 3 binary64) a)) < -0.095000000000000001

    1. Initial program 82.7%

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

    if -0.095000000000000001 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 #s(literal 3 binary64) a) c)))) (*.f64 #s(literal 3 binary64) a))

    1. Initial program 45.1%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. add-sqr-sqrt44.5%

        \[\leadsto \frac{\left(-\color{blue}{\sqrt{b} \cdot \sqrt{b}}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
      2. distribute-rgt-neg-in44.5%

        \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    4. Applied egg-rr44.5%

      \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    5. Step-by-step derivation
      1. clear-num44.5%

        \[\leadsto \color{blue}{\frac{1}{\frac{3 \cdot a}{\sqrt{b} \cdot \left(-\sqrt{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
      2. inv-pow44.5%

        \[\leadsto \color{blue}{{\left(\frac{3 \cdot a}{\sqrt{b} \cdot \left(-\sqrt{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1}} \]
      3. *-commutative44.5%

        \[\leadsto {\left(\frac{\color{blue}{a \cdot 3}}{\sqrt{b} \cdot \left(-\sqrt{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
      4. distribute-rgt-neg-out44.5%

        \[\leadsto {\left(\frac{a \cdot 3}{\color{blue}{\left(-\sqrt{b} \cdot \sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
      5. add-sqr-sqrt45.1%

        \[\leadsto {\left(\frac{a \cdot 3}{\left(-\color{blue}{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
      6. pow245.1%

        \[\leadsto {\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{\color{blue}{{b}^{2}} - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
      7. *-commutative45.1%

        \[\leadsto {\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - \color{blue}{c \cdot \left(3 \cdot a\right)}}}\right)}^{-1} \]
      8. *-commutative45.1%

        \[\leadsto {\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - c \cdot \color{blue}{\left(a \cdot 3\right)}}}\right)}^{-1} \]
    6. Applied egg-rr45.1%

      \[\leadsto \color{blue}{{\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}\right)}^{-1}} \]
    7. Step-by-step derivation
      1. unpow-145.1%

        \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}} \]
      2. +-commutative45.1%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\color{blue}{\sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)} + \left(-b\right)}}} \]
      3. unsub-neg45.1%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\color{blue}{\sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)} - b}}} \]
      4. unpow245.1%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\color{blue}{b \cdot b} - c \cdot \left(a \cdot 3\right)} - b}} \]
      5. fma-neg45.3%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\color{blue}{\mathsf{fma}\left(b, b, -c \cdot \left(a \cdot 3\right)\right)}} - b}} \]
      6. associate-*r*45.3%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(c \cdot a\right) \cdot 3}\right)} - b}} \]
      7. *-commutative45.3%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(a \cdot c\right)} \cdot 3\right)} - b}} \]
      8. distribute-rgt-neg-in45.3%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot \left(-3\right)}\right)} - b}} \]
      9. metadata-eval45.3%

        \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot \color{blue}{-3}\right)} - b}} \]
    8. Simplified45.3%

      \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -3\right)} - b}}} \]
    9. Taylor expanded in c around 0 89.7%

      \[\leadsto \frac{1}{\color{blue}{\frac{-2 \cdot b + 1.5 \cdot \frac{a \cdot c}{b}}{c}}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification88.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\sqrt{b \cdot b - c \cdot \left(3 \cdot a\right)} - b}{3 \cdot a} \leq -0.095:\\ \;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(3 \cdot a\right)} - b}{3 \cdot a}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\frac{b \cdot -2 + 1.5 \cdot \frac{c \cdot a}{b}}{c}}\\ \end{array} \]
  5. Add Preprocessing

Alternative 4: 99.1% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \frac{\frac{3 \cdot \left(c \cdot a\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -3\right)\right)}}}{3 \cdot a} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (/ (* 3.0 (* c a)) (- (- b) (sqrt (fma b b (* c (* a -3.0)))))) (* 3.0 a)))
double code(double a, double b, double c) {
	return ((3.0 * (c * a)) / (-b - sqrt(fma(b, b, (c * (a * -3.0)))))) / (3.0 * a);
}
function code(a, b, c)
	return Float64(Float64(Float64(3.0 * Float64(c * a)) / Float64(Float64(-b) - sqrt(fma(b, b, Float64(c * Float64(a * -3.0)))))) / Float64(3.0 * a))
end
code[a_, b_, c_] := N[(N[(N[(3.0 * N[(c * a), $MachinePrecision]), $MachinePrecision] / N[((-b) - N[Sqrt[N[(b * b + N[(c * N[(a * -3.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(3.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{3 \cdot \left(c \cdot a\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -3\right)\right)}}}{3 \cdot a}
\end{array}
Derivation
  1. Initial program 52.9%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-sqr-sqrt52.0%

      \[\leadsto \frac{\left(-\color{blue}{\sqrt{b} \cdot \sqrt{b}}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. distribute-rgt-neg-in52.0%

      \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  4. Applied egg-rr52.0%

    \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  5. Step-by-step derivation
    1. flip-+52.1%

      \[\leadsto \frac{\color{blue}{\frac{\left(\sqrt{b} \cdot \left(-\sqrt{b}\right)\right) \cdot \left(\sqrt{b} \cdot \left(-\sqrt{b}\right)\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}}{3 \cdot a} \]
    2. pow252.0%

      \[\leadsto \frac{\frac{\color{blue}{{\left(\sqrt{b} \cdot \left(-\sqrt{b}\right)\right)}^{2}} - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    3. distribute-rgt-neg-out52.0%

      \[\leadsto \frac{\frac{{\color{blue}{\left(-\sqrt{b} \cdot \sqrt{b}\right)}}^{2} - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    4. add-sqr-sqrt52.9%

      \[\leadsto \frac{\frac{{\left(-\color{blue}{b}\right)}^{2} - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c} \cdot \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    5. add-sqr-sqrt54.4%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \color{blue}{\left(b \cdot b - \left(3 \cdot a\right) \cdot c\right)}}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    6. pow254.4%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left(\color{blue}{{b}^{2}} - \left(3 \cdot a\right) \cdot c\right)}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    7. *-commutative54.4%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \color{blue}{c \cdot \left(3 \cdot a\right)}\right)}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    8. *-commutative54.4%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \color{blue}{\left(a \cdot 3\right)}\right)}{\sqrt{b} \cdot \left(-\sqrt{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    9. distribute-rgt-neg-out54.4%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 3\right)\right)}{\color{blue}{\left(-\sqrt{b} \cdot \sqrt{b}\right)} - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
    10. add-sqr-sqrt54.4%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 3\right)\right)}{\left(-\color{blue}{b}\right) - \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}{3 \cdot a} \]
  6. Applied egg-rr54.4%

    \[\leadsto \frac{\color{blue}{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 3\right)\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}}{3 \cdot a} \]
  7. Step-by-step derivation
    1. associate--r-99.3%

      \[\leadsto \frac{\frac{\color{blue}{\left({\left(-b\right)}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 3\right)}}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    2. unpow299.1%

      \[\leadsto \frac{\frac{\left(\color{blue}{\left(-b\right) \cdot \left(-b\right)} - {b}^{2}\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    3. unpow299.3%

      \[\leadsto \frac{\frac{\left(\left(-b\right) \cdot \left(-b\right) - \color{blue}{b \cdot b}\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    4. difference-of-squares99.3%

      \[\leadsto \frac{\frac{\color{blue}{\left(\left(-b\right) + b\right) \cdot \left(\left(-b\right) - b\right)} + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    5. neg-mul-199.3%

      \[\leadsto \frac{\frac{\left(\color{blue}{-1 \cdot b} + b\right) \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    6. distribute-lft1-in99.3%

      \[\leadsto \frac{\frac{\color{blue}{\left(\left(-1 + 1\right) \cdot b\right)} \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    7. metadata-eval99.3%

      \[\leadsto \frac{\frac{\left(\color{blue}{0} \cdot b\right) \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    8. mul0-lft99.3%

      \[\leadsto \frac{\frac{\color{blue}{0} \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    9. unpow299.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - c \cdot \left(a \cdot 3\right)}}}{3 \cdot a} \]
    10. fma-neg99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\color{blue}{\mathsf{fma}\left(b, b, -c \cdot \left(a \cdot 3\right)\right)}}}}{3 \cdot a} \]
    11. associate-*r*99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(c \cdot a\right) \cdot 3}\right)}}}{3 \cdot a} \]
    12. *-commutative99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(a \cdot c\right)} \cdot 3\right)}}}{3 \cdot a} \]
    13. distribute-rgt-neg-in99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot \left(-3\right)}\right)}}}{3 \cdot a} \]
    14. metadata-eval99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot \color{blue}{-3}\right)}}}{3 \cdot a} \]
  8. Simplified99.3%

    \[\leadsto \frac{\color{blue}{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -3\right)}}}}{3 \cdot a} \]
  9. Taylor expanded in a around 0 99.3%

    \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \color{blue}{-3 \cdot \left(a \cdot c\right)}\right)}}}{3 \cdot a} \]
  10. Step-by-step derivation
    1. associate-*r*99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(-3 \cdot a\right) \cdot c}\right)}}}{3 \cdot a} \]
    2. *-commutative99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot -3\right)} \cdot c\right)}}}{3 \cdot a} \]
    3. *-commutative99.3%

      \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \color{blue}{c \cdot \left(a \cdot -3\right)}\right)}}}{3 \cdot a} \]
  11. Simplified99.3%

    \[\leadsto \frac{\frac{0 \cdot \left(\left(-b\right) - b\right) + c \cdot \left(a \cdot 3\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \color{blue}{c \cdot \left(a \cdot -3\right)}\right)}}}{3 \cdot a} \]
  12. Taylor expanded in b around 0 99.1%

    \[\leadsto \frac{\frac{\color{blue}{3 \cdot \left(a \cdot c\right)}}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -3\right)\right)}}}{3 \cdot a} \]
  13. Final simplification99.1%

    \[\leadsto \frac{\frac{3 \cdot \left(c \cdot a\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -3\right)\right)}}}{3 \cdot a} \]
  14. Add Preprocessing

Alternative 5: 82.2% accurate, 7.7× speedup?

\[\begin{array}{l} \\ \frac{1}{\frac{b \cdot -2 + 1.5 \cdot \frac{c \cdot a}{b}}{c}} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ 1.0 (/ (+ (* b -2.0) (* 1.5 (/ (* c a) b))) c)))
double code(double a, double b, double c) {
	return 1.0 / (((b * -2.0) + (1.5 * ((c * a) / b))) / c);
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = 1.0d0 / (((b * (-2.0d0)) + (1.5d0 * ((c * a) / b))) / c)
end function
public static double code(double a, double b, double c) {
	return 1.0 / (((b * -2.0) + (1.5 * ((c * a) / b))) / c);
}
def code(a, b, c):
	return 1.0 / (((b * -2.0) + (1.5 * ((c * a) / b))) / c)
function code(a, b, c)
	return Float64(1.0 / Float64(Float64(Float64(b * -2.0) + Float64(1.5 * Float64(Float64(c * a) / b))) / c))
end
function tmp = code(a, b, c)
	tmp = 1.0 / (((b * -2.0) + (1.5 * ((c * a) / b))) / c);
end
code[a_, b_, c_] := N[(1.0 / N[(N[(N[(b * -2.0), $MachinePrecision] + N[(1.5 * N[(N[(c * a), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{\frac{b \cdot -2 + 1.5 \cdot \frac{c \cdot a}{b}}{c}}
\end{array}
Derivation
  1. Initial program 52.9%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-sqr-sqrt52.0%

      \[\leadsto \frac{\left(-\color{blue}{\sqrt{b} \cdot \sqrt{b}}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. distribute-rgt-neg-in52.0%

      \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  4. Applied egg-rr52.0%

    \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  5. Step-by-step derivation
    1. clear-num52.0%

      \[\leadsto \color{blue}{\frac{1}{\frac{3 \cdot a}{\sqrt{b} \cdot \left(-\sqrt{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
    2. inv-pow52.0%

      \[\leadsto \color{blue}{{\left(\frac{3 \cdot a}{\sqrt{b} \cdot \left(-\sqrt{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1}} \]
    3. *-commutative52.0%

      \[\leadsto {\left(\frac{\color{blue}{a \cdot 3}}{\sqrt{b} \cdot \left(-\sqrt{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
    4. distribute-rgt-neg-out52.0%

      \[\leadsto {\left(\frac{a \cdot 3}{\color{blue}{\left(-\sqrt{b} \cdot \sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
    5. add-sqr-sqrt52.9%

      \[\leadsto {\left(\frac{a \cdot 3}{\left(-\color{blue}{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
    6. pow252.9%

      \[\leadsto {\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{\color{blue}{{b}^{2}} - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
    7. *-commutative52.9%

      \[\leadsto {\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - \color{blue}{c \cdot \left(3 \cdot a\right)}}}\right)}^{-1} \]
    8. *-commutative52.9%

      \[\leadsto {\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - c \cdot \color{blue}{\left(a \cdot 3\right)}}}\right)}^{-1} \]
  6. Applied egg-rr52.9%

    \[\leadsto \color{blue}{{\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}\right)}^{-1}} \]
  7. Step-by-step derivation
    1. unpow-152.9%

      \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}} \]
    2. +-commutative52.9%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\color{blue}{\sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)} + \left(-b\right)}}} \]
    3. unsub-neg52.9%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\color{blue}{\sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)} - b}}} \]
    4. unpow252.9%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\color{blue}{b \cdot b} - c \cdot \left(a \cdot 3\right)} - b}} \]
    5. fma-neg53.0%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\color{blue}{\mathsf{fma}\left(b, b, -c \cdot \left(a \cdot 3\right)\right)}} - b}} \]
    6. associate-*r*53.0%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(c \cdot a\right) \cdot 3}\right)} - b}} \]
    7. *-commutative53.0%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(a \cdot c\right)} \cdot 3\right)} - b}} \]
    8. distribute-rgt-neg-in53.0%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot \left(-3\right)}\right)} - b}} \]
    9. metadata-eval53.0%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot \color{blue}{-3}\right)} - b}} \]
  8. Simplified53.0%

    \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -3\right)} - b}}} \]
  9. Taylor expanded in c around 0 83.7%

    \[\leadsto \frac{1}{\color{blue}{\frac{-2 \cdot b + 1.5 \cdot \frac{a \cdot c}{b}}{c}}} \]
  10. Final simplification83.7%

    \[\leadsto \frac{1}{\frac{b \cdot -2 + 1.5 \cdot \frac{c \cdot a}{b}}{c}} \]
  11. Add Preprocessing

Alternative 6: 82.2% accurate, 8.9× speedup?

\[\begin{array}{l} \\ \frac{1}{-2 \cdot \frac{b}{c} + 1.5 \cdot \frac{a}{b}} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ 1.0 (+ (* -2.0 (/ b c)) (* 1.5 (/ a b)))))
double code(double a, double b, double c) {
	return 1.0 / ((-2.0 * (b / c)) + (1.5 * (a / b)));
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = 1.0d0 / (((-2.0d0) * (b / c)) + (1.5d0 * (a / b)))
end function
public static double code(double a, double b, double c) {
	return 1.0 / ((-2.0 * (b / c)) + (1.5 * (a / b)));
}
def code(a, b, c):
	return 1.0 / ((-2.0 * (b / c)) + (1.5 * (a / b)))
function code(a, b, c)
	return Float64(1.0 / Float64(Float64(-2.0 * Float64(b / c)) + Float64(1.5 * Float64(a / b))))
end
function tmp = code(a, b, c)
	tmp = 1.0 / ((-2.0 * (b / c)) + (1.5 * (a / b)));
end
code[a_, b_, c_] := N[(1.0 / N[(N[(-2.0 * N[(b / c), $MachinePrecision]), $MachinePrecision] + N[(1.5 * N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{-2 \cdot \frac{b}{c} + 1.5 \cdot \frac{a}{b}}
\end{array}
Derivation
  1. Initial program 52.9%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-sqr-sqrt52.0%

      \[\leadsto \frac{\left(-\color{blue}{\sqrt{b} \cdot \sqrt{b}}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. distribute-rgt-neg-in52.0%

      \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  4. Applied egg-rr52.0%

    \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  5. Step-by-step derivation
    1. clear-num52.0%

      \[\leadsto \color{blue}{\frac{1}{\frac{3 \cdot a}{\sqrt{b} \cdot \left(-\sqrt{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}}} \]
    2. inv-pow52.0%

      \[\leadsto \color{blue}{{\left(\frac{3 \cdot a}{\sqrt{b} \cdot \left(-\sqrt{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1}} \]
    3. *-commutative52.0%

      \[\leadsto {\left(\frac{\color{blue}{a \cdot 3}}{\sqrt{b} \cdot \left(-\sqrt{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
    4. distribute-rgt-neg-out52.0%

      \[\leadsto {\left(\frac{a \cdot 3}{\color{blue}{\left(-\sqrt{b} \cdot \sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
    5. add-sqr-sqrt52.9%

      \[\leadsto {\left(\frac{a \cdot 3}{\left(-\color{blue}{b}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
    6. pow252.9%

      \[\leadsto {\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{\color{blue}{{b}^{2}} - \left(3 \cdot a\right) \cdot c}}\right)}^{-1} \]
    7. *-commutative52.9%

      \[\leadsto {\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - \color{blue}{c \cdot \left(3 \cdot a\right)}}}\right)}^{-1} \]
    8. *-commutative52.9%

      \[\leadsto {\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - c \cdot \color{blue}{\left(a \cdot 3\right)}}}\right)}^{-1} \]
  6. Applied egg-rr52.9%

    \[\leadsto \color{blue}{{\left(\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}\right)}^{-1}} \]
  7. Step-by-step derivation
    1. unpow-152.9%

      \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot 3}{\left(-b\right) + \sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)}}}} \]
    2. +-commutative52.9%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\color{blue}{\sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)} + \left(-b\right)}}} \]
    3. unsub-neg52.9%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\color{blue}{\sqrt{{b}^{2} - c \cdot \left(a \cdot 3\right)} - b}}} \]
    4. unpow252.9%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\color{blue}{b \cdot b} - c \cdot \left(a \cdot 3\right)} - b}} \]
    5. fma-neg53.0%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\color{blue}{\mathsf{fma}\left(b, b, -c \cdot \left(a \cdot 3\right)\right)}} - b}} \]
    6. associate-*r*53.0%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(c \cdot a\right) \cdot 3}\right)} - b}} \]
    7. *-commutative53.0%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(a \cdot c\right)} \cdot 3\right)} - b}} \]
    8. distribute-rgt-neg-in53.0%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot \left(-3\right)}\right)} - b}} \]
    9. metadata-eval53.0%

      \[\leadsto \frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot \color{blue}{-3}\right)} - b}} \]
  8. Simplified53.0%

    \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot 3}{\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -3\right)} - b}}} \]
  9. Taylor expanded in a around 0 83.7%

    \[\leadsto \frac{1}{\color{blue}{-2 \cdot \frac{b}{c} + 1.5 \cdot \frac{a}{b}}} \]
  10. Add Preprocessing

Alternative 7: 64.6% accurate, 23.2× speedup?

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

\\
-0.5 \cdot \frac{c}{b}
\end{array}
Derivation
  1. Initial program 52.9%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Step-by-step derivation
    1. /-rgt-identity52.9%

      \[\leadsto \frac{\color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{1}}}{3 \cdot a} \]
    2. metadata-eval52.9%

      \[\leadsto \frac{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{\color{blue}{-1 \cdot -1}}}{3 \cdot a} \]
  3. Simplified53.0%

    \[\leadsto \color{blue}{\frac{\sqrt{\mathsf{fma}\left(b, b, a \cdot \left(c \cdot -3\right)\right)} - b}{3 \cdot a}} \]
  4. Add Preprocessing
  5. Taylor expanded in b around inf 66.4%

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

Alternative 8: 3.2% accurate, 38.7× speedup?

\[\begin{array}{l} \\ \frac{0}{a} \end{array} \]
(FPCore (a b c) :precision binary64 (/ 0.0 a))
double code(double a, double b, double c) {
	return 0.0 / a;
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    code = 0.0d0 / a
end function
public static double code(double a, double b, double c) {
	return 0.0 / a;
}
def code(a, b, c):
	return 0.0 / a
function code(a, b, c)
	return Float64(0.0 / a)
end
function tmp = code(a, b, c)
	tmp = 0.0 / a;
end
code[a_, b_, c_] := N[(0.0 / a), $MachinePrecision]
\begin{array}{l}

\\
\frac{0}{a}
\end{array}
Derivation
  1. Initial program 52.9%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. add-sqr-sqrt52.0%

      \[\leadsto \frac{\left(-\color{blue}{\sqrt{b} \cdot \sqrt{b}}\right) + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
    2. distribute-rgt-neg-in52.0%

      \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  4. Applied egg-rr52.0%

    \[\leadsto \frac{\color{blue}{\sqrt{b} \cdot \left(-\sqrt{b}\right)} + \sqrt{b \cdot b - \left(3 \cdot a\right) \cdot c}}{3 \cdot a} \]
  5. Taylor expanded in a around 0 3.2%

    \[\leadsto \color{blue}{0.3333333333333333 \cdot \frac{b + -1 \cdot b}{a}} \]
  6. Step-by-step derivation
    1. associate-*r/3.2%

      \[\leadsto \color{blue}{\frac{0.3333333333333333 \cdot \left(b + -1 \cdot b\right)}{a}} \]
    2. distribute-rgt1-in3.2%

      \[\leadsto \frac{0.3333333333333333 \cdot \color{blue}{\left(\left(-1 + 1\right) \cdot b\right)}}{a} \]
    3. metadata-eval3.2%

      \[\leadsto \frac{0.3333333333333333 \cdot \left(\color{blue}{0} \cdot b\right)}{a} \]
    4. mul0-lft3.2%

      \[\leadsto \frac{0.3333333333333333 \cdot \color{blue}{0}}{a} \]
    5. metadata-eval3.2%

      \[\leadsto \frac{\color{blue}{0}}{a} \]
  7. Simplified3.2%

    \[\leadsto \color{blue}{\frac{0}{a}} \]
  8. Add Preprocessing

Reproduce

?
herbie shell --seed 2024143 
(FPCore (a b c)
  :name "Cubic critical, narrow range"
  :precision binary64
  :pre (and (and (and (< 1.0536712127723509e-8 a) (< a 94906265.62425156)) (and (< 1.0536712127723509e-8 b) (< b 94906265.62425156))) (and (< 1.0536712127723509e-8 c) (< c 94906265.62425156)))
  (/ (+ (- b) (sqrt (- (* b b) (* (* 3.0 a) c)))) (* 3.0 a)))