Quadratic roots, wide range

Percentage Accurate: 17.8% → 99.7%
Time: 59.7s
Alternatives: 5
Speedup: 29.0×

Specification

?
\[\left(\left(4.930380657631324 \cdot 10^{-32} < a \land a < 2.028240960365167 \cdot 10^{+31}\right) \land \left(4.930380657631324 \cdot 10^{-32} < b \land b < 2.028240960365167 \cdot 10^{+31}\right)\right) \land \left(4.930380657631324 \cdot 10^{-32} < c \land c < 2.028240960365167 \cdot 10^{+31}\right)\]
\[\begin{array}{l} \\ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \end{array} \]
(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 5 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: 17.8% 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: 99.7% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \frac{-1}{\frac{2}{\frac{c \cdot 4}{b + \sqrt{\mathsf{fma}\left(b, b, \left(c \cdot a\right) \cdot -4\right)}}}} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (/ -1.0 (/ 2.0 (/ (* c 4.0) (+ b (sqrt (fma b b (* (* c a) -4.0))))))))
double code(double a, double b, double c) {
	return -1.0 / (2.0 / ((c * 4.0) / (b + sqrt(fma(b, b, ((c * a) * -4.0))))));
}
function code(a, b, c)
	return Float64(-1.0 / Float64(2.0 / Float64(Float64(c * 4.0) / Float64(b + sqrt(fma(b, b, Float64(Float64(c * a) * -4.0)))))))
end
code[a_, b_, c_] := N[(-1.0 / N[(2.0 / N[(N[(c * 4.0), $MachinePrecision] / N[(b + N[Sqrt[N[(b * b + N[(N[(c * a), $MachinePrecision] * -4.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{-1}{\frac{2}{\frac{c \cdot 4}{b + \sqrt{\mathsf{fma}\left(b, b, \left(c \cdot a\right) \cdot -4\right)}}}}
\end{array}
Derivation
  1. Initial program 16.8%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative16.8%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified16.8%

    \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. add-exp-log16.8%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{e^{\log \left(\left(4 \cdot a\right) \cdot c\right)}}}}{a \cdot 2} \]
    2. associate-*l*16.8%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - e^{\log \color{blue}{\left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
  6. Applied egg-rr16.8%

    \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
  7. Step-by-step derivation
    1. flip-+16.7%

      \[\leadsto \frac{\color{blue}{\frac{\left(-b\right) \cdot \left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}} \cdot \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}}{a \cdot 2} \]
    2. pow216.7%

      \[\leadsto \frac{\frac{\color{blue}{{\left(-b\right)}^{2}} - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}} \cdot \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
    3. add-sqr-sqrt17.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \color{blue}{\left(b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}\right)}}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
    4. pow217.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left(\color{blue}{{b}^{2}} - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
    5. rem-exp-log17.2%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \color{blue}{4 \cdot \left(a \cdot c\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
    6. associate-*r*17.2%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \color{blue}{\left(4 \cdot a\right) \cdot c}\right)}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
    7. pow217.2%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \left(4 \cdot a\right) \cdot c\right)}{\left(-b\right) - \sqrt{\color{blue}{{b}^{2}} - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
    8. rem-exp-log17.2%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \left(4 \cdot a\right) \cdot c\right)}{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{4 \cdot \left(a \cdot c\right)}}}}{a \cdot 2} \]
    9. associate-*r*17.2%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \left(4 \cdot a\right) \cdot c\right)}{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{\left(4 \cdot a\right) \cdot c}}}}{a \cdot 2} \]
  8. Applied egg-rr17.2%

    \[\leadsto \frac{\color{blue}{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \left(4 \cdot a\right) \cdot c\right)}{\left(-b\right) - \sqrt{{b}^{2} - \left(4 \cdot a\right) \cdot c}}}}{a \cdot 2} \]
  9. Taylor expanded in b around 0 99.5%

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

      \[\leadsto \frac{\frac{\color{blue}{\left(a \cdot c\right) \cdot 4}}{\left(-b\right) - \sqrt{{b}^{2} - \left(4 \cdot a\right) \cdot c}}}{a \cdot 2} \]
    2. associate-*l*99.5%

      \[\leadsto \frac{\frac{\color{blue}{a \cdot \left(c \cdot 4\right)}}{\left(-b\right) - \sqrt{{b}^{2} - \left(4 \cdot a\right) \cdot c}}}{a \cdot 2} \]
  11. Simplified99.5%

    \[\leadsto \frac{\frac{\color{blue}{a \cdot \left(c \cdot 4\right)}}{\left(-b\right) - \sqrt{{b}^{2} - \left(4 \cdot a\right) \cdot c}}}{a \cdot 2} \]
  12. Step-by-step derivation
    1. clear-num99.3%

      \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot 2}{\frac{a \cdot \left(c \cdot 4\right)}{\left(-b\right) - \sqrt{{b}^{2} - \left(4 \cdot a\right) \cdot c}}}}} \]
    2. inv-pow99.3%

      \[\leadsto \color{blue}{{\left(\frac{a \cdot 2}{\frac{a \cdot \left(c \cdot 4\right)}{\left(-b\right) - \sqrt{{b}^{2} - \left(4 \cdot a\right) \cdot c}}}\right)}^{-1}} \]
    3. associate-/l*99.5%

      \[\leadsto {\left(\frac{a \cdot 2}{\color{blue}{a \cdot \frac{c \cdot 4}{\left(-b\right) - \sqrt{{b}^{2} - \left(4 \cdot a\right) \cdot c}}}}\right)}^{-1} \]
    4. *-commutative99.5%

      \[\leadsto {\left(\frac{a \cdot 2}{a \cdot \frac{c \cdot 4}{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{c \cdot \left(4 \cdot a\right)}}}}\right)}^{-1} \]
    5. *-commutative99.5%

      \[\leadsto {\left(\frac{a \cdot 2}{a \cdot \frac{c \cdot 4}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \color{blue}{\left(a \cdot 4\right)}}}}\right)}^{-1} \]
  13. Applied egg-rr99.5%

    \[\leadsto \color{blue}{{\left(\frac{a \cdot 2}{a \cdot \frac{c \cdot 4}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}}\right)}^{-1}} \]
  14. Step-by-step derivation
    1. unpow-199.5%

      \[\leadsto \color{blue}{\frac{1}{\frac{a \cdot 2}{a \cdot \frac{c \cdot 4}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}}}} \]
    2. times-frac99.7%

      \[\leadsto \frac{1}{\color{blue}{\frac{a}{a} \cdot \frac{2}{\frac{c \cdot 4}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}}}} \]
    3. *-inverses99.7%

      \[\leadsto \frac{1}{\color{blue}{1} \cdot \frac{2}{\frac{c \cdot 4}{\left(-b\right) - \sqrt{{b}^{2} - c \cdot \left(a \cdot 4\right)}}}} \]
    4. unpow299.7%

      \[\leadsto \frac{1}{1 \cdot \frac{2}{\frac{c \cdot 4}{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - c \cdot \left(a \cdot 4\right)}}}} \]
    5. associate-*r*99.7%

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

      \[\leadsto \frac{1}{1 \cdot \frac{2}{\frac{c \cdot 4}{\left(-b\right) - \sqrt{b \cdot b - \color{blue}{\left(a \cdot c\right)} \cdot 4}}}} \]
    7. associate-*r*99.7%

      \[\leadsto \frac{1}{1 \cdot \frac{2}{\frac{c \cdot 4}{\left(-b\right) - \sqrt{b \cdot b - \color{blue}{a \cdot \left(c \cdot 4\right)}}}}} \]
    8. fma-neg99.7%

      \[\leadsto \frac{1}{1 \cdot \frac{2}{\frac{c \cdot 4}{\left(-b\right) - \sqrt{\color{blue}{\mathsf{fma}\left(b, b, -a \cdot \left(c \cdot 4\right)\right)}}}}} \]
    9. associate-*r*99.7%

      \[\leadsto \frac{1}{1 \cdot \frac{2}{\frac{c \cdot 4}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(a \cdot c\right) \cdot 4}\right)}}}} \]
    10. distribute-rgt-neg-in99.7%

      \[\leadsto \frac{1}{1 \cdot \frac{2}{\frac{c \cdot 4}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot \left(-4\right)}\right)}}}} \]
    11. metadata-eval99.7%

      \[\leadsto \frac{1}{1 \cdot \frac{2}{\frac{c \cdot 4}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot \color{blue}{-4}\right)}}}} \]
  15. Simplified99.7%

    \[\leadsto \color{blue}{\frac{1}{1 \cdot \frac{2}{\frac{c \cdot 4}{\left(-b\right) - \sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)}}}}} \]
  16. Final simplification99.7%

    \[\leadsto \frac{-1}{\frac{2}{\frac{c \cdot 4}{b + \sqrt{\mathsf{fma}\left(b, b, \left(c \cdot a\right) \cdot -4\right)}}}} \]
  17. Add Preprocessing

Alternative 2: 99.4% accurate, 1.0× speedup?

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

\\
\frac{\frac{\left(c \cdot 4\right) \cdot a}{\left(-b\right) - \sqrt{b \cdot b - c \cdot \left(4 \cdot a\right)}}}{2 \cdot a}
\end{array}
Derivation
  1. Initial program 16.8%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative16.8%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified16.8%

    \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
  4. Add Preprocessing
  5. Step-by-step derivation
    1. add-exp-log16.8%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{e^{\log \left(\left(4 \cdot a\right) \cdot c\right)}}}}{a \cdot 2} \]
    2. associate-*l*16.8%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - e^{\log \color{blue}{\left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
  6. Applied egg-rr16.8%

    \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
  7. Step-by-step derivation
    1. flip-+16.7%

      \[\leadsto \frac{\color{blue}{\frac{\left(-b\right) \cdot \left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}} \cdot \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}}{a \cdot 2} \]
    2. pow216.7%

      \[\leadsto \frac{\frac{\color{blue}{{\left(-b\right)}^{2}} - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}} \cdot \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
    3. add-sqr-sqrt17.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \color{blue}{\left(b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}\right)}}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
    4. pow217.1%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left(\color{blue}{{b}^{2}} - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
    5. rem-exp-log17.2%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \color{blue}{4 \cdot \left(a \cdot c\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
    6. associate-*r*17.2%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \color{blue}{\left(4 \cdot a\right) \cdot c}\right)}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
    7. pow217.2%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \left(4 \cdot a\right) \cdot c\right)}{\left(-b\right) - \sqrt{\color{blue}{{b}^{2}} - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
    8. rem-exp-log17.2%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \left(4 \cdot a\right) \cdot c\right)}{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{4 \cdot \left(a \cdot c\right)}}}}{a \cdot 2} \]
    9. associate-*r*17.2%

      \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \left(4 \cdot a\right) \cdot c\right)}{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{\left(4 \cdot a\right) \cdot c}}}}{a \cdot 2} \]
  8. Applied egg-rr17.2%

    \[\leadsto \frac{\color{blue}{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \left(4 \cdot a\right) \cdot c\right)}{\left(-b\right) - \sqrt{{b}^{2} - \left(4 \cdot a\right) \cdot c}}}}{a \cdot 2} \]
  9. Taylor expanded in b around 0 99.5%

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

      \[\leadsto \frac{\frac{\color{blue}{\left(a \cdot c\right) \cdot 4}}{\left(-b\right) - \sqrt{{b}^{2} - \left(4 \cdot a\right) \cdot c}}}{a \cdot 2} \]
    2. associate-*l*99.5%

      \[\leadsto \frac{\frac{\color{blue}{a \cdot \left(c \cdot 4\right)}}{\left(-b\right) - \sqrt{{b}^{2} - \left(4 \cdot a\right) \cdot c}}}{a \cdot 2} \]
  11. Simplified99.5%

    \[\leadsto \frac{\frac{\color{blue}{a \cdot \left(c \cdot 4\right)}}{\left(-b\right) - \sqrt{{b}^{2} - \left(4 \cdot a\right) \cdot c}}}{a \cdot 2} \]
  12. Step-by-step derivation
    1. unpow299.5%

      \[\leadsto \frac{\frac{a \cdot \left(c \cdot 4\right)}{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - \left(4 \cdot a\right) \cdot c}}}{a \cdot 2} \]
  13. Applied egg-rr99.5%

    \[\leadsto \frac{\frac{a \cdot \left(c \cdot 4\right)}{\left(-b\right) - \sqrt{\color{blue}{b \cdot b} - \left(4 \cdot a\right) \cdot c}}}{a \cdot 2} \]
  14. Final simplification99.5%

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

Alternative 3: 95.3% accurate, 1.0× speedup?

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

\\
\frac{\left(-c\right) - a \cdot {\left(\frac{c}{-b}\right)}^{2}}{b}
\end{array}
Derivation
  1. Initial program 16.8%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative16.8%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified16.8%

    \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
  4. Add Preprocessing
  5. Taylor expanded in c around 0 97.2%

    \[\leadsto \color{blue}{c \cdot \left(c \cdot \left(-1 \cdot \frac{a}{{b}^{3}} + c \cdot \left(-2 \cdot \frac{{a}^{2}}{{b}^{5}} + -0.25 \cdot \frac{c \cdot \left(4 \cdot \frac{{a}^{4}}{{b}^{6}} + 16 \cdot \frac{{a}^{4}}{{b}^{6}}\right)}{a \cdot b}\right)\right) - \frac{1}{b}\right)} \]
  6. Step-by-step derivation
    1. Simplified97.2%

      \[\leadsto \color{blue}{c \cdot \left(c \cdot \mathsf{fma}\left(-1, \frac{a}{{b}^{3}}, c \cdot \mathsf{fma}\left(-2, \frac{{a}^{2}}{{b}^{5}}, -0.25 \cdot \left(c \cdot \frac{\frac{{a}^{4}}{{b}^{6}} \cdot 20}{a \cdot b}\right)\right)\right) - \frac{1}{b}\right)} \]
    2. Taylor expanded in b around inf 95.1%

      \[\leadsto \color{blue}{\frac{-1 \cdot c + -1 \cdot \frac{a \cdot {c}^{2}}{{b}^{2}}}{b}} \]
    3. Step-by-step derivation
      1. neg-mul-195.1%

        \[\leadsto \frac{\color{blue}{\left(-c\right)} + -1 \cdot \frac{a \cdot {c}^{2}}{{b}^{2}}}{b} \]
      2. mul-1-neg95.1%

        \[\leadsto \frac{\left(-c\right) + \color{blue}{\left(-\frac{a \cdot {c}^{2}}{{b}^{2}}\right)}}{b} \]
      3. unsub-neg95.1%

        \[\leadsto \frac{\color{blue}{\left(-c\right) - \frac{a \cdot {c}^{2}}{{b}^{2}}}}{b} \]
      4. associate-/l*95.1%

        \[\leadsto \frac{\left(-c\right) - \color{blue}{a \cdot \frac{{c}^{2}}{{b}^{2}}}}{b} \]
      5. unpow295.1%

        \[\leadsto \frac{\left(-c\right) - a \cdot \frac{\color{blue}{c \cdot c}}{{b}^{2}}}{b} \]
      6. unpow295.1%

        \[\leadsto \frac{\left(-c\right) - a \cdot \frac{c \cdot c}{\color{blue}{b \cdot b}}}{b} \]
      7. times-frac95.1%

        \[\leadsto \frac{\left(-c\right) - a \cdot \color{blue}{\left(\frac{c}{b} \cdot \frac{c}{b}\right)}}{b} \]
      8. sqr-neg95.1%

        \[\leadsto \frac{\left(-c\right) - a \cdot \color{blue}{\left(\left(-\frac{c}{b}\right) \cdot \left(-\frac{c}{b}\right)\right)}}{b} \]
      9. distribute-frac-neg95.1%

        \[\leadsto \frac{\left(-c\right) - a \cdot \left(\color{blue}{\frac{-c}{b}} \cdot \left(-\frac{c}{b}\right)\right)}{b} \]
      10. distribute-frac-neg95.1%

        \[\leadsto \frac{\left(-c\right) - a \cdot \left(\frac{-c}{b} \cdot \color{blue}{\frac{-c}{b}}\right)}{b} \]
      11. unpow195.1%

        \[\leadsto \frac{\left(-c\right) - a \cdot \left(\color{blue}{{\left(\frac{-c}{b}\right)}^{1}} \cdot \frac{-c}{b}\right)}{b} \]
      12. pow-plus95.1%

        \[\leadsto \frac{\left(-c\right) - a \cdot \color{blue}{{\left(\frac{-c}{b}\right)}^{\left(1 + 1\right)}}}{b} \]
      13. distribute-frac-neg95.1%

        \[\leadsto \frac{\left(-c\right) - a \cdot {\color{blue}{\left(-\frac{c}{b}\right)}}^{\left(1 + 1\right)}}{b} \]
      14. distribute-neg-frac295.1%

        \[\leadsto \frac{\left(-c\right) - a \cdot {\color{blue}{\left(\frac{c}{-b}\right)}}^{\left(1 + 1\right)}}{b} \]
      15. metadata-eval95.1%

        \[\leadsto \frac{\left(-c\right) - a \cdot {\left(\frac{c}{-b}\right)}^{\color{blue}{2}}}{b} \]
    4. Simplified95.1%

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

    Alternative 4: 95.1% accurate, 6.1× speedup?

    \[\begin{array}{l} \\ \frac{\frac{\left(c \cdot 4\right) \cdot a}{2 \cdot \left(a \cdot \frac{c}{b} - b\right)}}{2 \cdot a} \end{array} \]
    (FPCore (a b c)
     :precision binary64
     (/ (/ (* (* c 4.0) a) (* 2.0 (- (* a (/ c b)) b))) (* 2.0 a)))
    double code(double a, double b, double c) {
    	return (((c * 4.0) * a) / (2.0 * ((a * (c / b)) - b))) / (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 = (((c * 4.0d0) * a) / (2.0d0 * ((a * (c / b)) - b))) / (2.0d0 * a)
    end function
    
    public static double code(double a, double b, double c) {
    	return (((c * 4.0) * a) / (2.0 * ((a * (c / b)) - b))) / (2.0 * a);
    }
    
    def code(a, b, c):
    	return (((c * 4.0) * a) / (2.0 * ((a * (c / b)) - b))) / (2.0 * a)
    
    function code(a, b, c)
    	return Float64(Float64(Float64(Float64(c * 4.0) * a) / Float64(2.0 * Float64(Float64(a * Float64(c / b)) - b))) / Float64(2.0 * a))
    end
    
    function tmp = code(a, b, c)
    	tmp = (((c * 4.0) * a) / (2.0 * ((a * (c / b)) - b))) / (2.0 * a);
    end
    
    code[a_, b_, c_] := N[(N[(N[(N[(c * 4.0), $MachinePrecision] * a), $MachinePrecision] / N[(2.0 * N[(N[(a * N[(c / b), $MachinePrecision]), $MachinePrecision] - b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{\frac{\left(c \cdot 4\right) \cdot a}{2 \cdot \left(a \cdot \frac{c}{b} - b\right)}}{2 \cdot a}
    \end{array}
    
    Derivation
    1. Initial program 16.8%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. *-commutative16.8%

        \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
    3. Simplified16.8%

      \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
    4. Add Preprocessing
    5. Step-by-step derivation
      1. add-exp-log16.8%

        \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{e^{\log \left(\left(4 \cdot a\right) \cdot c\right)}}}}{a \cdot 2} \]
      2. associate-*l*16.8%

        \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - e^{\log \color{blue}{\left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
    6. Applied egg-rr16.8%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \color{blue}{e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
    7. Step-by-step derivation
      1. flip-+16.7%

        \[\leadsto \frac{\color{blue}{\frac{\left(-b\right) \cdot \left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}} \cdot \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}}{a \cdot 2} \]
      2. pow216.7%

        \[\leadsto \frac{\frac{\color{blue}{{\left(-b\right)}^{2}} - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}} \cdot \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
      3. add-sqr-sqrt17.1%

        \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \color{blue}{\left(b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}\right)}}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
      4. pow217.1%

        \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left(\color{blue}{{b}^{2}} - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
      5. rem-exp-log17.2%

        \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \color{blue}{4 \cdot \left(a \cdot c\right)}\right)}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
      6. associate-*r*17.2%

        \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \color{blue}{\left(4 \cdot a\right) \cdot c}\right)}{\left(-b\right) - \sqrt{b \cdot b - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
      7. pow217.2%

        \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \left(4 \cdot a\right) \cdot c\right)}{\left(-b\right) - \sqrt{\color{blue}{{b}^{2}} - e^{\log \left(4 \cdot \left(a \cdot c\right)\right)}}}}{a \cdot 2} \]
      8. rem-exp-log17.2%

        \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \left(4 \cdot a\right) \cdot c\right)}{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{4 \cdot \left(a \cdot c\right)}}}}{a \cdot 2} \]
      9. associate-*r*17.2%

        \[\leadsto \frac{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \left(4 \cdot a\right) \cdot c\right)}{\left(-b\right) - \sqrt{{b}^{2} - \color{blue}{\left(4 \cdot a\right) \cdot c}}}}{a \cdot 2} \]
    8. Applied egg-rr17.2%

      \[\leadsto \frac{\color{blue}{\frac{{\left(-b\right)}^{2} - \left({b}^{2} - \left(4 \cdot a\right) \cdot c\right)}{\left(-b\right) - \sqrt{{b}^{2} - \left(4 \cdot a\right) \cdot c}}}}{a \cdot 2} \]
    9. Taylor expanded in b around 0 99.5%

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

        \[\leadsto \frac{\frac{\color{blue}{\left(a \cdot c\right) \cdot 4}}{\left(-b\right) - \sqrt{{b}^{2} - \left(4 \cdot a\right) \cdot c}}}{a \cdot 2} \]
      2. associate-*l*99.5%

        \[\leadsto \frac{\frac{\color{blue}{a \cdot \left(c \cdot 4\right)}}{\left(-b\right) - \sqrt{{b}^{2} - \left(4 \cdot a\right) \cdot c}}}{a \cdot 2} \]
    11. Simplified99.5%

      \[\leadsto \frac{\frac{\color{blue}{a \cdot \left(c \cdot 4\right)}}{\left(-b\right) - \sqrt{{b}^{2} - \left(4 \cdot a\right) \cdot c}}}{a \cdot 2} \]
    12. Taylor expanded in a around 0 94.9%

      \[\leadsto \frac{\frac{a \cdot \left(c \cdot 4\right)}{\color{blue}{2 \cdot \frac{a \cdot c}{b} - 2 \cdot b}}}{a \cdot 2} \]
    13. Step-by-step derivation
      1. distribute-lft-out--94.9%

        \[\leadsto \frac{\frac{a \cdot \left(c \cdot 4\right)}{\color{blue}{2 \cdot \left(\frac{a \cdot c}{b} - b\right)}}}{a \cdot 2} \]
      2. associate-/l*94.9%

        \[\leadsto \frac{\frac{a \cdot \left(c \cdot 4\right)}{2 \cdot \left(\color{blue}{a \cdot \frac{c}{b}} - b\right)}}{a \cdot 2} \]
    14. Simplified94.9%

      \[\leadsto \frac{\frac{a \cdot \left(c \cdot 4\right)}{\color{blue}{2 \cdot \left(a \cdot \frac{c}{b} - b\right)}}}{a \cdot 2} \]
    15. Final simplification94.9%

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

    Alternative 5: 90.4% 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 16.8%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. *-commutative16.8%

        \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
    3. Simplified16.8%

      \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
    4. Add Preprocessing
    5. Taylor expanded in b around inf 91.0%

      \[\leadsto \color{blue}{-1 \cdot \frac{c}{b}} \]
    6. Step-by-step derivation
      1. associate-*r/91.0%

        \[\leadsto \color{blue}{\frac{-1 \cdot c}{b}} \]
      2. mul-1-neg91.0%

        \[\leadsto \frac{\color{blue}{-c}}{b} \]
    7. Simplified91.0%

      \[\leadsto \color{blue}{\frac{-c}{b}} \]
    8. Final simplification91.0%

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

    Reproduce

    ?
    herbie shell --seed 2024116 
    (FPCore (a b c)
      :name "Quadratic roots, wide range"
      :precision binary64
      :pre (and (and (and (< 4.930380657631324e-32 a) (< a 2.028240960365167e+31)) (and (< 4.930380657631324e-32 b) (< b 2.028240960365167e+31))) (and (< 4.930380657631324e-32 c) (< c 2.028240960365167e+31)))
      (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))