Quadratic roots, narrow range

Percentage Accurate: 55.4% → 99.3%
Time: 13.6s
Alternatives: 7
Speedup: 29.0×

Specification

?
\[\left(\left(1.0536712127723509 \cdot 10^{-8} < a \land a < 94906265.62425156\right) \land \left(1.0536712127723509 \cdot 10^{-8} < b \land b < 94906265.62425156\right)\right) \land \left(1.0536712127723509 \cdot 10^{-8} < c \land c < 94906265.62425156\right)\]
\[\begin{array}{l} \\ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))
double code(double a, double b, double c) {
	return (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * 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) - ((4.0d0 * a) * c)))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
	return (-b + Math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
def code(a, b, c):
	return (-b + math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a)
function code(a, b, c)
	return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))) / Float64(2.0 * a))
end
function tmp = code(a, b, c)
	tmp = (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \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: 55.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))
double code(double a, double b, double c) {
	return (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * 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) - ((4.0d0 * a) * c)))) / (2.0d0 * a)
end function
public static double code(double a, double b, double c) {
	return (-b + Math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
}
def code(a, b, c):
	return (-b + math.sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a)
function code(a, b, c)
	return Float64(Float64(Float64(-b) + sqrt(Float64(Float64(b * b) - Float64(Float64(4.0 * a) * c)))) / Float64(2.0 * a))
end
function tmp = code(a, b, c)
	tmp = (-b + sqrt(((b * b) - ((4.0 * a) * c)))) / (2.0 * a);
end
code[a_, b_, c_] := N[(N[((-b) + N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(N[(4.0 * a), $MachinePrecision] * c), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a}
\end{array}

Alternative 1: 99.3% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := c \cdot \left(4 \cdot a\right)\\ \frac{t\_0}{\left(a \cdot 2\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - t\_0}\right)} \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (let* ((t_0 (* c (* 4.0 a))))
   (/ t_0 (* (* a 2.0) (- (- b) (sqrt (- (pow b 2.0) t_0)))))))
double code(double a, double b, double c) {
	double t_0 = c * (4.0 * a);
	return t_0 / ((a * 2.0) * (-b - sqrt((pow(b, 2.0) - t_0))));
}
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 = c * (4.0d0 * a)
    code = t_0 / ((a * 2.0d0) * (-b - sqrt(((b ** 2.0d0) - t_0))))
end function
public static double code(double a, double b, double c) {
	double t_0 = c * (4.0 * a);
	return t_0 / ((a * 2.0) * (-b - Math.sqrt((Math.pow(b, 2.0) - t_0))));
}
def code(a, b, c):
	t_0 = c * (4.0 * a)
	return t_0 / ((a * 2.0) * (-b - math.sqrt((math.pow(b, 2.0) - t_0))))
function code(a, b, c)
	t_0 = Float64(c * Float64(4.0 * a))
	return Float64(t_0 / Float64(Float64(a * 2.0) * Float64(Float64(-b) - sqrt(Float64((b ^ 2.0) - t_0)))))
end
function tmp = code(a, b, c)
	t_0 = c * (4.0 * a);
	tmp = t_0 / ((a * 2.0) * (-b - sqrt(((b ^ 2.0) - t_0))));
end
code[a_, b_, c_] := Block[{t$95$0 = N[(c * N[(4.0 * a), $MachinePrecision]), $MachinePrecision]}, N[(t$95$0 / N[(N[(a * 2.0), $MachinePrecision] * N[((-b) - N[Sqrt[N[(N[Power[b, 2.0], $MachinePrecision] - t$95$0), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := c \cdot \left(4 \cdot a\right)\\
\frac{t\_0}{\left(a \cdot 2\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - t\_0}\right)}
\end{array}
\end{array}
Derivation
  1. Initial program 57.4%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative57.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified57.4%

    \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. add-cbrt-cube57.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{\sqrt[3]{\left(\left(4 \cdot a\right) \cdot \left(4 \cdot a\right)\right) \cdot \left(4 \cdot a\right)}} \cdot c}}{a \cdot 2} \]
    2. pow357.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \sqrt[3]{\color{blue}{{\left(4 \cdot a\right)}^{3}}} \cdot c}}{a \cdot 2} \]
  6. Applied egg-rr57.4%

    \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{\sqrt[3]{{\left(4 \cdot a\right)}^{3}}} \cdot c}}{a \cdot 2} \]
  7. Step-by-step derivation
    1. flip-+57.4%

      \[\leadsto \frac{\color{blue}{\frac{\left(-b\right) \cdot \left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c} \cdot \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}}{a \cdot 2} \]
    2. pow257.4%

      \[\leadsto \frac{\frac{\color{blue}{{\left(-b\right)}^{2}} - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c} \cdot \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    3. add-sqr-sqrt59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \color{blue}{\left(b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c\right)}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    4. pow259.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left(\color{blue}{{b}^{2}} - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    5. *-commutative59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \color{blue}{c \cdot \sqrt[3]{{\left(4 \cdot a\right)}^{3}}}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    6. unpow359.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \sqrt[3]{\color{blue}{\left(\left(4 \cdot a\right) \cdot \left(4 \cdot a\right)\right) \cdot \left(4 \cdot a\right)}}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    7. add-cbrt-cube59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \color{blue}{\left(4 \cdot a\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    8. *-commutative59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \color{blue}{\left(a \cdot 4\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
  8. Applied egg-rr59.1%

    \[\leadsto \frac{\color{blue}{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
  9. Step-by-step derivation
    1. *-un-lft-identity59.1%

      \[\leadsto \color{blue}{1 \cdot \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}}{a \cdot 2}} \]
    2. associate-/l/59.1%

      \[\leadsto 1 \cdot \color{blue}{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}{\left(a \cdot 2\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right)}} \]
    3. associate--r-99.4%

      \[\leadsto 1 \cdot \frac{\color{blue}{\left({\left(-b\right)}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}{\left(a \cdot 2\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right)} \]
    4. neg-mul-199.4%

      \[\leadsto 1 \cdot \frac{\left({\color{blue}{\left(-1 \cdot b\right)}}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}{\left(a \cdot 2\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right)} \]
    5. unpow-prod-down99.4%

      \[\leadsto 1 \cdot \frac{\left(\color{blue}{{-1}^{2} \cdot {b}^{2}} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}{\left(a \cdot 2\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right)} \]
    6. metadata-eval99.4%

      \[\leadsto 1 \cdot \frac{\left(\color{blue}{1} \cdot {b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}{\left(a \cdot 2\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right)} \]
    7. *-un-lft-identity99.4%

      \[\leadsto 1 \cdot \frac{\left(\color{blue}{{b}^{2}} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}{\left(a \cdot 2\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right)} \]
    8. *-commutative99.4%

      \[\leadsto 1 \cdot \frac{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}{\color{blue}{\left(2 \cdot a\right)} \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right)} \]
  10. Applied egg-rr99.4%

    \[\leadsto \color{blue}{1 \cdot \frac{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}{\left(2 \cdot a\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right)}} \]
  11. Step-by-step derivation
    1. *-un-lft-identity99.4%

      \[\leadsto \color{blue}{\frac{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}{\left(2 \cdot a\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right)}} \]
    2. +-commutative99.4%

      \[\leadsto \frac{\color{blue}{c \cdot \left(a \cdot 4\right) + \left({b}^{2} - {b}^{2}\right)}}{\left(2 \cdot a\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right)} \]
    3. fma-define99.4%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(c, a \cdot 4, {b}^{2} - {b}^{2}\right)}}{\left(2 \cdot a\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right)} \]
    4. +-inverses99.4%

      \[\leadsto \frac{\mathsf{fma}\left(c, a \cdot 4, \color{blue}{0}\right)}{\left(2 \cdot a\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right)} \]
    5. *-commutative99.4%

      \[\leadsto \frac{\mathsf{fma}\left(c, a \cdot 4, 0\right)}{\color{blue}{\left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right) \cdot \left(2 \cdot a\right)}} \]
  12. Applied egg-rr99.4%

    \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(c, a \cdot 4, 0\right)}{\left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right) \cdot \left(2 \cdot a\right)}} \]
  13. Step-by-step derivation
    1. fma-undefine99.4%

      \[\leadsto \frac{\color{blue}{c \cdot \left(a \cdot 4\right) + 0}}{\left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right) \cdot \left(2 \cdot a\right)} \]
    2. +-rgt-identity99.4%

      \[\leadsto \frac{\color{blue}{c \cdot \left(a \cdot 4\right)}}{\left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right) \cdot \left(2 \cdot a\right)} \]
    3. *-commutative99.4%

      \[\leadsto \frac{c \cdot \color{blue}{\left(4 \cdot a\right)}}{\left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right) \cdot \left(2 \cdot a\right)} \]
    4. *-commutative99.4%

      \[\leadsto \frac{c \cdot \left(4 \cdot a\right)}{\color{blue}{\left(2 \cdot a\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right)}} \]
    5. *-commutative99.4%

      \[\leadsto \frac{c \cdot \left(4 \cdot a\right)}{\color{blue}{\left(a \cdot 2\right)} \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}\right)} \]
    6. *-commutative99.4%

      \[\leadsto \frac{c \cdot \left(4 \cdot a\right)}{\left(a \cdot 2\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \color{blue}{\left(4 \cdot a\right)}}\right)} \]
  14. Simplified99.4%

    \[\leadsto \color{blue}{\frac{c \cdot \left(4 \cdot a\right)}{\left(a \cdot 2\right) \cdot \left(\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(4 \cdot a\right)}\right)}} \]
  15. Add Preprocessing

Alternative 2: 88.0% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \frac{\frac{1}{\frac{-0.5 \cdot \frac{b}{c} + a \cdot \left(0.5 \cdot \frac{c \cdot a}{{b}^{3}} + 0.5 \cdot \frac{1}{b}\right)}{a}}}{a \cdot 2} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/
  (/
   1.0
   (/
    (+
     (* -0.5 (/ b c))
     (* a (+ (* 0.5 (/ (* c a) (pow b 3.0))) (* 0.5 (/ 1.0 b)))))
    a))
  (* a 2.0)))
double code(double a, double b, double c) {
	return (1.0 / (((-0.5 * (b / c)) + (a * ((0.5 * ((c * a) / pow(b, 3.0))) + (0.5 * (1.0 / b))))) / a)) / (a * 2.0);
}
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 / ((((-0.5d0) * (b / c)) + (a * ((0.5d0 * ((c * a) / (b ** 3.0d0))) + (0.5d0 * (1.0d0 / b))))) / a)) / (a * 2.0d0)
end function
public static double code(double a, double b, double c) {
	return (1.0 / (((-0.5 * (b / c)) + (a * ((0.5 * ((c * a) / Math.pow(b, 3.0))) + (0.5 * (1.0 / b))))) / a)) / (a * 2.0);
}
def code(a, b, c):
	return (1.0 / (((-0.5 * (b / c)) + (a * ((0.5 * ((c * a) / math.pow(b, 3.0))) + (0.5 * (1.0 / b))))) / a)) / (a * 2.0)
function code(a, b, c)
	return Float64(Float64(1.0 / Float64(Float64(Float64(-0.5 * Float64(b / c)) + Float64(a * Float64(Float64(0.5 * Float64(Float64(c * a) / (b ^ 3.0))) + Float64(0.5 * Float64(1.0 / b))))) / a)) / Float64(a * 2.0))
end
function tmp = code(a, b, c)
	tmp = (1.0 / (((-0.5 * (b / c)) + (a * ((0.5 * ((c * a) / (b ^ 3.0))) + (0.5 * (1.0 / b))))) / a)) / (a * 2.0);
end
code[a_, b_, c_] := N[(N[(1.0 / N[(N[(N[(-0.5 * N[(b / c), $MachinePrecision]), $MachinePrecision] + N[(a * N[(N[(0.5 * N[(N[(c * a), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(1.0 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{1}{\frac{-0.5 \cdot \frac{b}{c} + a \cdot \left(0.5 \cdot \frac{c \cdot a}{{b}^{3}} + 0.5 \cdot \frac{1}{b}\right)}{a}}}{a \cdot 2}
\end{array}
Derivation
  1. Initial program 57.4%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative57.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified57.4%

    \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. add-cbrt-cube57.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{\sqrt[3]{\left(\left(4 \cdot a\right) \cdot \left(4 \cdot a\right)\right) \cdot \left(4 \cdot a\right)}} \cdot c}}{a \cdot 2} \]
    2. pow357.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \sqrt[3]{\color{blue}{{\left(4 \cdot a\right)}^{3}}} \cdot c}}{a \cdot 2} \]
  6. Applied egg-rr57.4%

    \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{\sqrt[3]{{\left(4 \cdot a\right)}^{3}}} \cdot c}}{a \cdot 2} \]
  7. Step-by-step derivation
    1. flip-+57.4%

      \[\leadsto \frac{\color{blue}{\frac{\left(-b\right) \cdot \left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c} \cdot \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}}{a \cdot 2} \]
    2. pow257.4%

      \[\leadsto \frac{\frac{\color{blue}{{\left(-b\right)}^{2}} - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c} \cdot \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    3. add-sqr-sqrt59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \color{blue}{\left(b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c\right)}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    4. pow259.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left(\color{blue}{{b}^{2}} - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    5. *-commutative59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \color{blue}{c \cdot \sqrt[3]{{\left(4 \cdot a\right)}^{3}}}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    6. unpow359.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \sqrt[3]{\color{blue}{\left(\left(4 \cdot a\right) \cdot \left(4 \cdot a\right)\right) \cdot \left(4 \cdot a\right)}}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    7. add-cbrt-cube59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \color{blue}{\left(4 \cdot a\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    8. *-commutative59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \color{blue}{\left(a \cdot 4\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
  8. Applied egg-rr59.1%

    \[\leadsto \frac{\color{blue}{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
  9. Step-by-step derivation
    1. clear-num59.1%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}}}}{a \cdot 2} \]
    2. inv-pow59.1%

      \[\leadsto \frac{\color{blue}{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}\right)}^{-1}}}{a \cdot 2} \]
    3. associate--r-99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\color{blue}{\left({\left(-b\right)}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}\right)}^{-1}}{a \cdot 2} \]
    4. neg-mul-199.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left({\color{blue}{\left(-1 \cdot b\right)}}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
    5. unpow-prod-down99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left(\color{blue}{{-1}^{2} \cdot {b}^{2}} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
    6. metadata-eval99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left(\color{blue}{1} \cdot {b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
    7. *-un-lft-identity99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left(\color{blue}{{b}^{2}} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
  10. Applied egg-rr99.4%

    \[\leadsto \frac{\color{blue}{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}}{a \cdot 2} \]
  11. Step-by-step derivation
    1. unpow-199.4%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
    2. associate-*r*99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{\left(c \cdot a\right) \cdot 4}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    3. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{\left(a \cdot c\right)} \cdot 4}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    4. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{4 \cdot \left(a \cdot c\right)}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    5. cancel-sign-sub-inv99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{{b}^{2} + \left(-4\right) \cdot \left(a \cdot c\right)}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    6. metadata-eval99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} + \color{blue}{-4} \cdot \left(a \cdot c\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    7. +-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{-4 \cdot \left(a \cdot c\right) + {b}^{2}}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    8. fma-define99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{\mathsf{fma}\left(-4, a \cdot c, {b}^{2}\right)}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    9. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, \color{blue}{c \cdot a}, {b}^{2}\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    10. +-inverses99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{0} + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    11. +-lft-identity99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
    12. associate-*r*99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{\left(c \cdot a\right) \cdot 4}}}}{a \cdot 2} \]
    13. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{4 \cdot \left(c \cdot a\right)}}}}{a \cdot 2} \]
    14. associate-*r*99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{\left(4 \cdot c\right) \cdot a}}}}{a \cdot 2} \]
    15. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{\left(c \cdot 4\right)} \cdot a}}}{a \cdot 2} \]
  12. Simplified99.4%

    \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\left(c \cdot 4\right) \cdot a}}}}{a \cdot 2} \]
  13. Taylor expanded in a around 0 88.4%

    \[\leadsto \frac{\frac{1}{\color{blue}{\frac{-0.5 \cdot \frac{b}{c} + a \cdot \left(0.5 \cdot \frac{a \cdot c}{{b}^{3}} + 0.5 \cdot \frac{1}{b}\right)}{a}}}}{a \cdot 2} \]
  14. Final simplification88.4%

    \[\leadsto \frac{\frac{1}{\frac{-0.5 \cdot \frac{b}{c} + a \cdot \left(0.5 \cdot \frac{c \cdot a}{{b}^{3}} + 0.5 \cdot \frac{1}{b}\right)}{a}}}{a \cdot 2} \]
  15. Add Preprocessing

Alternative 3: 87.9% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \frac{\frac{1}{\frac{-0.5 \cdot \frac{b}{a} + c \cdot \left(0.5 \cdot \frac{c \cdot a}{{b}^{3}} + 0.5 \cdot \frac{1}{b}\right)}{c}}}{a \cdot 2} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/
  (/
   1.0
   (/
    (+
     (* -0.5 (/ b a))
     (* c (+ (* 0.5 (/ (* c a) (pow b 3.0))) (* 0.5 (/ 1.0 b)))))
    c))
  (* a 2.0)))
double code(double a, double b, double c) {
	return (1.0 / (((-0.5 * (b / a)) + (c * ((0.5 * ((c * a) / pow(b, 3.0))) + (0.5 * (1.0 / b))))) / c)) / (a * 2.0);
}
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 / ((((-0.5d0) * (b / a)) + (c * ((0.5d0 * ((c * a) / (b ** 3.0d0))) + (0.5d0 * (1.0d0 / b))))) / c)) / (a * 2.0d0)
end function
public static double code(double a, double b, double c) {
	return (1.0 / (((-0.5 * (b / a)) + (c * ((0.5 * ((c * a) / Math.pow(b, 3.0))) + (0.5 * (1.0 / b))))) / c)) / (a * 2.0);
}
def code(a, b, c):
	return (1.0 / (((-0.5 * (b / a)) + (c * ((0.5 * ((c * a) / math.pow(b, 3.0))) + (0.5 * (1.0 / b))))) / c)) / (a * 2.0)
function code(a, b, c)
	return Float64(Float64(1.0 / Float64(Float64(Float64(-0.5 * Float64(b / a)) + Float64(c * Float64(Float64(0.5 * Float64(Float64(c * a) / (b ^ 3.0))) + Float64(0.5 * Float64(1.0 / b))))) / c)) / Float64(a * 2.0))
end
function tmp = code(a, b, c)
	tmp = (1.0 / (((-0.5 * (b / a)) + (c * ((0.5 * ((c * a) / (b ^ 3.0))) + (0.5 * (1.0 / b))))) / c)) / (a * 2.0);
end
code[a_, b_, c_] := N[(N[(1.0 / N[(N[(N[(-0.5 * N[(b / a), $MachinePrecision]), $MachinePrecision] + N[(c * N[(N[(0.5 * N[(N[(c * a), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(1.0 / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{1}{\frac{-0.5 \cdot \frac{b}{a} + c \cdot \left(0.5 \cdot \frac{c \cdot a}{{b}^{3}} + 0.5 \cdot \frac{1}{b}\right)}{c}}}{a \cdot 2}
\end{array}
Derivation
  1. Initial program 57.4%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative57.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified57.4%

    \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. add-cbrt-cube57.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{\sqrt[3]{\left(\left(4 \cdot a\right) \cdot \left(4 \cdot a\right)\right) \cdot \left(4 \cdot a\right)}} \cdot c}}{a \cdot 2} \]
    2. pow357.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \sqrt[3]{\color{blue}{{\left(4 \cdot a\right)}^{3}}} \cdot c}}{a \cdot 2} \]
  6. Applied egg-rr57.4%

    \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{\sqrt[3]{{\left(4 \cdot a\right)}^{3}}} \cdot c}}{a \cdot 2} \]
  7. Step-by-step derivation
    1. flip-+57.4%

      \[\leadsto \frac{\color{blue}{\frac{\left(-b\right) \cdot \left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c} \cdot \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}}{a \cdot 2} \]
    2. pow257.4%

      \[\leadsto \frac{\frac{\color{blue}{{\left(-b\right)}^{2}} - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c} \cdot \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    3. add-sqr-sqrt59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \color{blue}{\left(b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c\right)}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    4. pow259.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left(\color{blue}{{b}^{2}} - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    5. *-commutative59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \color{blue}{c \cdot \sqrt[3]{{\left(4 \cdot a\right)}^{3}}}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    6. unpow359.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \sqrt[3]{\color{blue}{\left(\left(4 \cdot a\right) \cdot \left(4 \cdot a\right)\right) \cdot \left(4 \cdot a\right)}}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    7. add-cbrt-cube59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \color{blue}{\left(4 \cdot a\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    8. *-commutative59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \color{blue}{\left(a \cdot 4\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
  8. Applied egg-rr59.1%

    \[\leadsto \frac{\color{blue}{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
  9. Step-by-step derivation
    1. clear-num59.1%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}}}}{a \cdot 2} \]
    2. inv-pow59.1%

      \[\leadsto \frac{\color{blue}{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}\right)}^{-1}}}{a \cdot 2} \]
    3. associate--r-99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\color{blue}{\left({\left(-b\right)}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}\right)}^{-1}}{a \cdot 2} \]
    4. neg-mul-199.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left({\color{blue}{\left(-1 \cdot b\right)}}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
    5. unpow-prod-down99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left(\color{blue}{{-1}^{2} \cdot {b}^{2}} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
    6. metadata-eval99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left(\color{blue}{1} \cdot {b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
    7. *-un-lft-identity99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left(\color{blue}{{b}^{2}} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
  10. Applied egg-rr99.4%

    \[\leadsto \frac{\color{blue}{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}}{a \cdot 2} \]
  11. Step-by-step derivation
    1. unpow-199.4%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
    2. associate-*r*99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{\left(c \cdot a\right) \cdot 4}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    3. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{\left(a \cdot c\right)} \cdot 4}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    4. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{4 \cdot \left(a \cdot c\right)}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    5. cancel-sign-sub-inv99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{{b}^{2} + \left(-4\right) \cdot \left(a \cdot c\right)}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    6. metadata-eval99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} + \color{blue}{-4} \cdot \left(a \cdot c\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    7. +-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{-4 \cdot \left(a \cdot c\right) + {b}^{2}}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    8. fma-define99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{\mathsf{fma}\left(-4, a \cdot c, {b}^{2}\right)}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    9. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, \color{blue}{c \cdot a}, {b}^{2}\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    10. +-inverses99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{0} + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    11. +-lft-identity99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
    12. associate-*r*99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{\left(c \cdot a\right) \cdot 4}}}}{a \cdot 2} \]
    13. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{4 \cdot \left(c \cdot a\right)}}}}{a \cdot 2} \]
    14. associate-*r*99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{\left(4 \cdot c\right) \cdot a}}}}{a \cdot 2} \]
    15. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{\left(c \cdot 4\right)} \cdot a}}}{a \cdot 2} \]
  12. Simplified99.4%

    \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\left(c \cdot 4\right) \cdot a}}}}{a \cdot 2} \]
  13. Taylor expanded in c around 0 88.4%

    \[\leadsto \frac{\frac{1}{\color{blue}{\frac{-0.5 \cdot \frac{b}{a} + c \cdot \left(0.5 \cdot \frac{a \cdot c}{{b}^{3}} + 0.5 \cdot \frac{1}{b}\right)}{c}}}}{a \cdot 2} \]
  14. Final simplification88.4%

    \[\leadsto \frac{\frac{1}{\frac{-0.5 \cdot \frac{b}{a} + c \cdot \left(0.5 \cdot \frac{c \cdot a}{{b}^{3}} + 0.5 \cdot \frac{1}{b}\right)}{c}}}{a \cdot 2} \]
  15. Add Preprocessing

Alternative 4: 85.3% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;b \leq 17:\\ \;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(4 \cdot a\right)} - b}{a \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{1}{\frac{-0.5 \cdot \frac{b}{a} + 0.5 \cdot \frac{c}{b}}{c}}}{a \cdot 2}\\ \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (if (<= b 17.0)
   (/ (- (sqrt (- (* b b) (* c (* 4.0 a)))) b) (* a 2.0))
   (/ (/ 1.0 (/ (+ (* -0.5 (/ b a)) (* 0.5 (/ c b))) c)) (* a 2.0))))
double code(double a, double b, double c) {
	double tmp;
	if (b <= 17.0) {
		tmp = (sqrt(((b * b) - (c * (4.0 * a)))) - b) / (a * 2.0);
	} else {
		tmp = (1.0 / (((-0.5 * (b / a)) + (0.5 * (c / b))) / c)) / (a * 2.0);
	}
	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) :: tmp
    if (b <= 17.0d0) then
        tmp = (sqrt(((b * b) - (c * (4.0d0 * a)))) - b) / (a * 2.0d0)
    else
        tmp = (1.0d0 / ((((-0.5d0) * (b / a)) + (0.5d0 * (c / b))) / c)) / (a * 2.0d0)
    end if
    code = tmp
end function
public static double code(double a, double b, double c) {
	double tmp;
	if (b <= 17.0) {
		tmp = (Math.sqrt(((b * b) - (c * (4.0 * a)))) - b) / (a * 2.0);
	} else {
		tmp = (1.0 / (((-0.5 * (b / a)) + (0.5 * (c / b))) / c)) / (a * 2.0);
	}
	return tmp;
}
def code(a, b, c):
	tmp = 0
	if b <= 17.0:
		tmp = (math.sqrt(((b * b) - (c * (4.0 * a)))) - b) / (a * 2.0)
	else:
		tmp = (1.0 / (((-0.5 * (b / a)) + (0.5 * (c / b))) / c)) / (a * 2.0)
	return tmp
function code(a, b, c)
	tmp = 0.0
	if (b <= 17.0)
		tmp = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(4.0 * a)))) - b) / Float64(a * 2.0));
	else
		tmp = Float64(Float64(1.0 / Float64(Float64(Float64(-0.5 * Float64(b / a)) + Float64(0.5 * Float64(c / b))) / c)) / Float64(a * 2.0));
	end
	return tmp
end
function tmp_2 = code(a, b, c)
	tmp = 0.0;
	if (b <= 17.0)
		tmp = (sqrt(((b * b) - (c * (4.0 * a)))) - b) / (a * 2.0);
	else
		tmp = (1.0 / (((-0.5 * (b / a)) + (0.5 * (c / b))) / c)) / (a * 2.0);
	end
	tmp_2 = tmp;
end
code[a_, b_, c_] := If[LessEqual[b, 17.0], N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(4.0 * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / N[(N[(N[(-0.5 * N[(b / a), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;b \leq 17:\\
\;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(4 \cdot a\right)} - b}{a \cdot 2}\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{1}{\frac{-0.5 \cdot \frac{b}{a} + 0.5 \cdot \frac{c}{b}}{c}}}{a \cdot 2}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if b < 17

    1. Initial program 78.0%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    2. Add Preprocessing

    if 17 < b

    1. Initial program 50.0%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. *-commutative50.0%

        \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
    3. Simplified50.0%

      \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. add-cbrt-cube50.0%

        \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{\sqrt[3]{\left(\left(4 \cdot a\right) \cdot \left(4 \cdot a\right)\right) \cdot \left(4 \cdot a\right)}} \cdot c}}{a \cdot 2} \]
      2. pow350.0%

        \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \sqrt[3]{\color{blue}{{\left(4 \cdot a\right)}^{3}}} \cdot c}}{a \cdot 2} \]
    6. Applied egg-rr50.0%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{\sqrt[3]{{\left(4 \cdot a\right)}^{3}}} \cdot c}}{a \cdot 2} \]
    7. Step-by-step derivation
      1. flip-+49.9%

        \[\leadsto \frac{\color{blue}{\frac{\left(-b\right) \cdot \left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c} \cdot \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}}{a \cdot 2} \]
      2. pow249.9%

        \[\leadsto \frac{\frac{\color{blue}{{\left(-b\right)}^{2}} - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c} \cdot \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
      3. add-sqr-sqrt51.6%

        \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \color{blue}{\left(b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c\right)}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
      4. pow251.6%

        \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left(\color{blue}{{b}^{2}} - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
      5. *-commutative51.6%

        \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \color{blue}{c \cdot \sqrt[3]{{\left(4 \cdot a\right)}^{3}}}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
      6. unpow351.6%

        \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \sqrt[3]{\color{blue}{\left(\left(4 \cdot a\right) \cdot \left(4 \cdot a\right)\right) \cdot \left(4 \cdot a\right)}}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
      7. add-cbrt-cube51.6%

        \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \color{blue}{\left(4 \cdot a\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
      8. *-commutative51.6%

        \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \color{blue}{\left(a \cdot 4\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    8. Applied egg-rr51.6%

      \[\leadsto \frac{\color{blue}{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
    9. Step-by-step derivation
      1. clear-num51.6%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}}}}{a \cdot 2} \]
      2. inv-pow51.6%

        \[\leadsto \frac{\color{blue}{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}\right)}^{-1}}}{a \cdot 2} \]
      3. associate--r-99.4%

        \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\color{blue}{\left({\left(-b\right)}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}\right)}^{-1}}{a \cdot 2} \]
      4. neg-mul-199.4%

        \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left({\color{blue}{\left(-1 \cdot b\right)}}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
      5. unpow-prod-down99.4%

        \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left(\color{blue}{{-1}^{2} \cdot {b}^{2}} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
      6. metadata-eval99.4%

        \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left(\color{blue}{1} \cdot {b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
      7. *-un-lft-identity99.4%

        \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left(\color{blue}{{b}^{2}} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
    10. Applied egg-rr99.4%

      \[\leadsto \frac{\color{blue}{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}}{a \cdot 2} \]
    11. Step-by-step derivation
      1. unpow-199.4%

        \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
      2. associate-*r*99.4%

        \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{\left(c \cdot a\right) \cdot 4}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
      3. *-commutative99.4%

        \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{\left(a \cdot c\right)} \cdot 4}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
      4. *-commutative99.4%

        \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{4 \cdot \left(a \cdot c\right)}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
      5. cancel-sign-sub-inv99.4%

        \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{{b}^{2} + \left(-4\right) \cdot \left(a \cdot c\right)}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
      6. metadata-eval99.4%

        \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} + \color{blue}{-4} \cdot \left(a \cdot c\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
      7. +-commutative99.4%

        \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{-4 \cdot \left(a \cdot c\right) + {b}^{2}}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
      8. fma-define99.4%

        \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{\mathsf{fma}\left(-4, a \cdot c, {b}^{2}\right)}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
      9. *-commutative99.4%

        \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, \color{blue}{c \cdot a}, {b}^{2}\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
      10. +-inverses99.4%

        \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{0} + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
      11. +-lft-identity99.4%

        \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
      12. associate-*r*99.4%

        \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{\left(c \cdot a\right) \cdot 4}}}}{a \cdot 2} \]
      13. *-commutative99.4%

        \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{4 \cdot \left(c \cdot a\right)}}}}{a \cdot 2} \]
      14. associate-*r*99.4%

        \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{\left(4 \cdot c\right) \cdot a}}}}{a \cdot 2} \]
      15. *-commutative99.4%

        \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{\left(c \cdot 4\right)} \cdot a}}}{a \cdot 2} \]
    12. Simplified99.4%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\left(c \cdot 4\right) \cdot a}}}}{a \cdot 2} \]
    13. Taylor expanded in c around 0 87.4%

      \[\leadsto \frac{\frac{1}{\color{blue}{\frac{-0.5 \cdot \frac{b}{a} + 0.5 \cdot \frac{c}{b}}{c}}}}{a \cdot 2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification84.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;b \leq 17:\\ \;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(4 \cdot a\right)} - b}{a \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{1}{\frac{-0.5 \cdot \frac{b}{a} + 0.5 \cdot \frac{c}{b}}{c}}}{a \cdot 2}\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 81.7% accurate, 6.1× speedup?

\[\begin{array}{l} \\ \frac{\frac{1}{\frac{-0.5 \cdot \frac{b}{c} + 0.5 \cdot \frac{a}{b}}{a}}}{a \cdot 2} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (/ 1.0 (/ (+ (* -0.5 (/ b c)) (* 0.5 (/ a b))) a)) (* a 2.0)))
double code(double a, double b, double c) {
	return (1.0 / (((-0.5 * (b / c)) + (0.5 * (a / b))) / a)) / (a * 2.0);
}
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 / ((((-0.5d0) * (b / c)) + (0.5d0 * (a / b))) / a)) / (a * 2.0d0)
end function
public static double code(double a, double b, double c) {
	return (1.0 / (((-0.5 * (b / c)) + (0.5 * (a / b))) / a)) / (a * 2.0);
}
def code(a, b, c):
	return (1.0 / (((-0.5 * (b / c)) + (0.5 * (a / b))) / a)) / (a * 2.0)
function code(a, b, c)
	return Float64(Float64(1.0 / Float64(Float64(Float64(-0.5 * Float64(b / c)) + Float64(0.5 * Float64(a / b))) / a)) / Float64(a * 2.0))
end
function tmp = code(a, b, c)
	tmp = (1.0 / (((-0.5 * (b / c)) + (0.5 * (a / b))) / a)) / (a * 2.0);
end
code[a_, b_, c_] := N[(N[(1.0 / N[(N[(N[(-0.5 * N[(b / c), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(a / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{1}{\frac{-0.5 \cdot \frac{b}{c} + 0.5 \cdot \frac{a}{b}}{a}}}{a \cdot 2}
\end{array}
Derivation
  1. Initial program 57.4%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative57.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified57.4%

    \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. add-cbrt-cube57.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{\sqrt[3]{\left(\left(4 \cdot a\right) \cdot \left(4 \cdot a\right)\right) \cdot \left(4 \cdot a\right)}} \cdot c}}{a \cdot 2} \]
    2. pow357.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \sqrt[3]{\color{blue}{{\left(4 \cdot a\right)}^{3}}} \cdot c}}{a \cdot 2} \]
  6. Applied egg-rr57.4%

    \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{\sqrt[3]{{\left(4 \cdot a\right)}^{3}}} \cdot c}}{a \cdot 2} \]
  7. Step-by-step derivation
    1. flip-+57.4%

      \[\leadsto \frac{\color{blue}{\frac{\left(-b\right) \cdot \left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c} \cdot \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}}{a \cdot 2} \]
    2. pow257.4%

      \[\leadsto \frac{\frac{\color{blue}{{\left(-b\right)}^{2}} - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c} \cdot \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    3. add-sqr-sqrt59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \color{blue}{\left(b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c\right)}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    4. pow259.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left(\color{blue}{{b}^{2}} - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    5. *-commutative59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \color{blue}{c \cdot \sqrt[3]{{\left(4 \cdot a\right)}^{3}}}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    6. unpow359.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \sqrt[3]{\color{blue}{\left(\left(4 \cdot a\right) \cdot \left(4 \cdot a\right)\right) \cdot \left(4 \cdot a\right)}}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    7. add-cbrt-cube59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \color{blue}{\left(4 \cdot a\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    8. *-commutative59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \color{blue}{\left(a \cdot 4\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
  8. Applied egg-rr59.1%

    \[\leadsto \frac{\color{blue}{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
  9. Step-by-step derivation
    1. clear-num59.1%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}}}}{a \cdot 2} \]
    2. inv-pow59.1%

      \[\leadsto \frac{\color{blue}{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}\right)}^{-1}}}{a \cdot 2} \]
    3. associate--r-99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\color{blue}{\left({\left(-b\right)}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}\right)}^{-1}}{a \cdot 2} \]
    4. neg-mul-199.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left({\color{blue}{\left(-1 \cdot b\right)}}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
    5. unpow-prod-down99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left(\color{blue}{{-1}^{2} \cdot {b}^{2}} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
    6. metadata-eval99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left(\color{blue}{1} \cdot {b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
    7. *-un-lft-identity99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left(\color{blue}{{b}^{2}} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
  10. Applied egg-rr99.4%

    \[\leadsto \frac{\color{blue}{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}}{a \cdot 2} \]
  11. Step-by-step derivation
    1. unpow-199.4%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
    2. associate-*r*99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{\left(c \cdot a\right) \cdot 4}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    3. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{\left(a \cdot c\right)} \cdot 4}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    4. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{4 \cdot \left(a \cdot c\right)}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    5. cancel-sign-sub-inv99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{{b}^{2} + \left(-4\right) \cdot \left(a \cdot c\right)}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    6. metadata-eval99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} + \color{blue}{-4} \cdot \left(a \cdot c\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    7. +-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{-4 \cdot \left(a \cdot c\right) + {b}^{2}}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    8. fma-define99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{\mathsf{fma}\left(-4, a \cdot c, {b}^{2}\right)}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    9. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, \color{blue}{c \cdot a}, {b}^{2}\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    10. +-inverses99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{0} + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    11. +-lft-identity99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
    12. associate-*r*99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{\left(c \cdot a\right) \cdot 4}}}}{a \cdot 2} \]
    13. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{4 \cdot \left(c \cdot a\right)}}}}{a \cdot 2} \]
    14. associate-*r*99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{\left(4 \cdot c\right) \cdot a}}}}{a \cdot 2} \]
    15. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{\left(c \cdot 4\right)} \cdot a}}}{a \cdot 2} \]
  12. Simplified99.4%

    \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\left(c \cdot 4\right) \cdot a}}}}{a \cdot 2} \]
  13. Taylor expanded in a around 0 81.9%

    \[\leadsto \frac{\frac{1}{\color{blue}{\frac{-0.5 \cdot \frac{b}{c} + 0.5 \cdot \frac{a}{b}}{a}}}}{a \cdot 2} \]
  14. Add Preprocessing

Alternative 6: 81.7% accurate, 6.1× speedup?

\[\begin{array}{l} \\ \frac{\frac{1}{\frac{-0.5 \cdot \frac{b}{a} + 0.5 \cdot \frac{c}{b}}{c}}}{a \cdot 2} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ (/ 1.0 (/ (+ (* -0.5 (/ b a)) (* 0.5 (/ c b))) c)) (* a 2.0)))
double code(double a, double b, double c) {
	return (1.0 / (((-0.5 * (b / a)) + (0.5 * (c / b))) / c)) / (a * 2.0);
}
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 / ((((-0.5d0) * (b / a)) + (0.5d0 * (c / b))) / c)) / (a * 2.0d0)
end function
public static double code(double a, double b, double c) {
	return (1.0 / (((-0.5 * (b / a)) + (0.5 * (c / b))) / c)) / (a * 2.0);
}
def code(a, b, c):
	return (1.0 / (((-0.5 * (b / a)) + (0.5 * (c / b))) / c)) / (a * 2.0)
function code(a, b, c)
	return Float64(Float64(1.0 / Float64(Float64(Float64(-0.5 * Float64(b / a)) + Float64(0.5 * Float64(c / b))) / c)) / Float64(a * 2.0))
end
function tmp = code(a, b, c)
	tmp = (1.0 / (((-0.5 * (b / a)) + (0.5 * (c / b))) / c)) / (a * 2.0);
end
code[a_, b_, c_] := N[(N[(1.0 / N[(N[(N[(-0.5 * N[(b / a), $MachinePrecision]), $MachinePrecision] + N[(0.5 * N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / c), $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\frac{1}{\frac{-0.5 \cdot \frac{b}{a} + 0.5 \cdot \frac{c}{b}}{c}}}{a \cdot 2}
\end{array}
Derivation
  1. Initial program 57.4%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative57.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified57.4%

    \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. add-cbrt-cube57.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{\sqrt[3]{\left(\left(4 \cdot a\right) \cdot \left(4 \cdot a\right)\right) \cdot \left(4 \cdot a\right)}} \cdot c}}{a \cdot 2} \]
    2. pow357.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \sqrt[3]{\color{blue}{{\left(4 \cdot a\right)}^{3}}} \cdot c}}{a \cdot 2} \]
  6. Applied egg-rr57.4%

    \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{\sqrt[3]{{\left(4 \cdot a\right)}^{3}}} \cdot c}}{a \cdot 2} \]
  7. Step-by-step derivation
    1. flip-+57.4%

      \[\leadsto \frac{\color{blue}{\frac{\left(-b\right) \cdot \left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c} \cdot \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}}{a \cdot 2} \]
    2. pow257.4%

      \[\leadsto \frac{\frac{\color{blue}{{\left(-b\right)}^{2}} - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c} \cdot \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    3. add-sqr-sqrt59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \color{blue}{\left(b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c\right)}}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    4. pow259.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left(\color{blue}{{b}^{2}} - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    5. *-commutative59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \color{blue}{c \cdot \sqrt[3]{{\left(4 \cdot a\right)}^{3}}}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    6. unpow359.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \sqrt[3]{\color{blue}{\left(\left(4 \cdot a\right) \cdot \left(4 \cdot a\right)\right) \cdot \left(4 \cdot a\right)}}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    7. add-cbrt-cube59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \color{blue}{\left(4 \cdot a\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
    8. *-commutative59.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \color{blue}{\left(a \cdot 4\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - \sqrt[3]{{\left(4 \cdot a\right)}^{3}} \cdot c}}}{a \cdot 2} \]
  8. Applied egg-rr59.1%

    \[\leadsto \frac{\color{blue}{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
  9. Step-by-step derivation
    1. clear-num59.1%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}}}}{a \cdot 2} \]
    2. inv-pow59.1%

      \[\leadsto \frac{\color{blue}{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{{\left(-b\right)}^{2} - \left({b}^{2} - c \cdot \left(a \cdot 4\right)\right)}\right)}^{-1}}}{a \cdot 2} \]
    3. associate--r-99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\color{blue}{\left({\left(-b\right)}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}\right)}^{-1}}{a \cdot 2} \]
    4. neg-mul-199.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left({\color{blue}{\left(-1 \cdot b\right)}}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
    5. unpow-prod-down99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left(\color{blue}{{-1}^{2} \cdot {b}^{2}} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
    6. metadata-eval99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left(\color{blue}{1} \cdot {b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
    7. *-un-lft-identity99.4%

      \[\leadsto \frac{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left(\color{blue}{{b}^{2}} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}{a \cdot 2} \]
  10. Applied egg-rr99.4%

    \[\leadsto \frac{\color{blue}{{\left(\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}\right)}^{-1}}}{a \cdot 2} \]
  11. Step-by-step derivation
    1. unpow-199.4%

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
    2. associate-*r*99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{\left(c \cdot a\right) \cdot 4}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    3. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{\left(a \cdot c\right)} \cdot 4}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    4. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{4 \cdot \left(a \cdot c\right)}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    5. cancel-sign-sub-inv99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{{b}^{2} + \left(-4\right) \cdot \left(a \cdot c\right)}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    6. metadata-eval99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{{b}^{2} + \color{blue}{-4} \cdot \left(a \cdot c\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    7. +-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{-4 \cdot \left(a \cdot c\right) + {b}^{2}}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    8. fma-define99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{\mathsf{fma}\left(-4, a \cdot c, {b}^{2}\right)}}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    9. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, \color{blue}{c \cdot a}, {b}^{2}\right)}}{\left({b}^{2} - {b}^{2}\right) + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    10. +-inverses99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{0} + c \cdot \left(a \cdot 4\right)}}}{a \cdot 2} \]
    11. +-lft-identity99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{c \cdot \left(a \cdot 4\right)}}}}{a \cdot 2} \]
    12. associate-*r*99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{\left(c \cdot a\right) \cdot 4}}}}{a \cdot 2} \]
    13. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{4 \cdot \left(c \cdot a\right)}}}}{a \cdot 2} \]
    14. associate-*r*99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{\left(4 \cdot c\right) \cdot a}}}}{a \cdot 2} \]
    15. *-commutative99.4%

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\color{blue}{\left(c \cdot 4\right)} \cdot a}}}{a \cdot 2} \]
  12. Simplified99.4%

    \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, {b}^{2}\right)}}{\left(c \cdot 4\right) \cdot a}}}}{a \cdot 2} \]
  13. Taylor expanded in c around 0 81.9%

    \[\leadsto \frac{\frac{1}{\color{blue}{\frac{-0.5 \cdot \frac{b}{a} + 0.5 \cdot \frac{c}{b}}{c}}}}{a \cdot 2} \]
  14. Add Preprocessing

Alternative 7: 64.3% accurate, 29.0× speedup?

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

\\
\frac{c}{-b}
\end{array}
Derivation
  1. Initial program 57.4%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative57.4%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified57.5%

    \[\leadsto \color{blue}{\frac{\sqrt{\mathsf{fma}\left(b, b, c \cdot \left(a \cdot -4\right)\right)} - b}{a \cdot 2}} \]
  4. Add Preprocessing
  5. Taylor expanded in b around inf 63.1%

    \[\leadsto \color{blue}{-1 \cdot \frac{c}{b}} \]
  6. Step-by-step derivation
    1. associate-*r/63.1%

      \[\leadsto \color{blue}{\frac{-1 \cdot c}{b}} \]
    2. mul-1-neg63.1%

      \[\leadsto \frac{\color{blue}{-c}}{b} \]
  7. Simplified63.1%

    \[\leadsto \color{blue}{\frac{-c}{b}} \]
  8. Final simplification63.1%

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

Reproduce

?
herbie shell --seed 2024179 
(FPCore (a b c)
  :name "Quadratic roots, 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) (* (* 4.0 a) c)))) (* 2.0 a)))