Quadratic roots, medium range

Percentage Accurate: 31.4% → 95.5%
Time: 10.7s
Alternatives: 6
Speedup: 29.0×

Specification

?
\[\left(\left(1.1102230246251565 \cdot 10^{-16} < a \land a < 9007199254740992\right) \land \left(1.1102230246251565 \cdot 10^{-16} < b \land b < 9007199254740992\right)\right) \land \left(1.1102230246251565 \cdot 10^{-16} < c \land c < 9007199254740992\right)\]
\[\begin{array}{l} \\ \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \end{array} \]
(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 6 alternatives:

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

Initial Program: 31.4% 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: 95.5% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \left(\mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{\frac{-5 \cdot \left({a}^{3} \cdot {c}^{4}\right)}{{b}^{6}}}{b}\right) - \frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (-
  (-
   (fma
    -2.0
    (/ (pow c 3.0) (/ (pow b 5.0) (* a a)))
    (/ (/ (* -5.0 (* (pow a 3.0) (pow c 4.0))) (pow b 6.0)) b))
   (/ c b))
  (/ (* c c) (/ (pow b 3.0) a))))
double code(double a, double b, double c) {
	return (fma(-2.0, (pow(c, 3.0) / (pow(b, 5.0) / (a * a))), (((-5.0 * (pow(a, 3.0) * pow(c, 4.0))) / pow(b, 6.0)) / b)) - (c / b)) - ((c * c) / (pow(b, 3.0) / a));
}
function code(a, b, c)
	return Float64(Float64(fma(-2.0, Float64((c ^ 3.0) / Float64((b ^ 5.0) / Float64(a * a))), Float64(Float64(Float64(-5.0 * Float64((a ^ 3.0) * (c ^ 4.0))) / (b ^ 6.0)) / b)) - Float64(c / b)) - Float64(Float64(c * c) / Float64((b ^ 3.0) / a)))
end
code[a_, b_, c_] := N[(N[(N[(-2.0 * N[(N[Power[c, 3.0], $MachinePrecision] / N[(N[Power[b, 5.0], $MachinePrecision] / N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(-5.0 * N[(N[Power[a, 3.0], $MachinePrecision] * N[Power[c, 4.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[b, 6.0], $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision] - N[(N[(c * c), $MachinePrecision] / N[(N[Power[b, 3.0], $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{\frac{-5 \cdot \left({a}^{3} \cdot {c}^{4}\right)}{{b}^{6}}}{b}\right) - \frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}}
\end{array}
Derivation
  1. Initial program 28.1%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. /-rgt-identity28.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{\frac{2 \cdot a}{1}}} \]
    2. metadata-eval28.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\frac{2 \cdot a}{\color{blue}{--1}}} \]
    3. associate-/l*28.1%

      \[\leadsto \color{blue}{\frac{\left(\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\right) \cdot \left(--1\right)}{2 \cdot a}} \]
    4. associate-*r/28.1%

      \[\leadsto \color{blue}{\left(\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\right) \cdot \frac{--1}{2 \cdot a}} \]
    5. +-commutative28.1%

      \[\leadsto \color{blue}{\left(\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c} + \left(-b\right)\right)} \cdot \frac{--1}{2 \cdot a} \]
    6. unsub-neg28.1%

      \[\leadsto \color{blue}{\left(\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c} - b\right)} \cdot \frac{--1}{2 \cdot a} \]
    7. fma-neg28.1%

      \[\leadsto \left(\sqrt{\color{blue}{\mathsf{fma}\left(b, b, -\left(4 \cdot a\right) \cdot c\right)}} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    8. associate-*l*28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{4 \cdot \left(a \cdot c\right)}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    9. *-commutative28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(a \cdot c\right) \cdot 4}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    10. distribute-rgt-neg-in28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot \left(-4\right)}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    11. metadata-eval28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot \color{blue}{-4}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    12. associate-/r*28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \color{blue}{\frac{\frac{--1}{2}}{a}} \]
    13. metadata-eval28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{\frac{\color{blue}{1}}{2}}{a} \]
    14. metadata-eval28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{\color{blue}{0.5}}{a} \]
  3. Simplified28.1%

    \[\leadsto \color{blue}{\left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{0.5}{a}} \]
  4. Taylor expanded in a around 0 96.9%

    \[\leadsto \color{blue}{-1 \cdot \frac{{c}^{2} \cdot a}{{b}^{3}} + \left(-1 \cdot \frac{c}{b} + \left(-0.25 \cdot \frac{{a}^{3} \cdot \left(16 \cdot \frac{{c}^{4}}{{b}^{6}} + {\left(-2 \cdot \frac{{c}^{2}}{{b}^{3}}\right)}^{2}\right)}{b} + -2 \cdot \frac{{c}^{3} \cdot {a}^{2}}{{b}^{5}}\right)\right)} \]
  5. Simplified96.9%

    \[\leadsto \color{blue}{\left(\mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{\left(-0.25 \cdot {a}^{3}\right) \cdot \mathsf{fma}\left(16, \frac{{c}^{4}}{{b}^{6}}, 4 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right) - \frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}}} \]
  6. Taylor expanded in c around 0 96.9%

    \[\leadsto \left(\mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{\color{blue}{-5 \cdot \frac{{c}^{4} \cdot {a}^{3}}{{b}^{6}}}}{b}\right) - \frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}} \]
  7. Step-by-step derivation
    1. associate-*r/96.9%

      \[\leadsto \left(\mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{\color{blue}{\frac{-5 \cdot \left({c}^{4} \cdot {a}^{3}\right)}{{b}^{6}}}}{b}\right) - \frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}} \]
    2. *-commutative96.9%

      \[\leadsto \left(\mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{\frac{-5 \cdot \color{blue}{\left({a}^{3} \cdot {c}^{4}\right)}}{{b}^{6}}}{b}\right) - \frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}} \]
  8. Simplified96.9%

    \[\leadsto \left(\mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{\color{blue}{\frac{-5 \cdot \left({a}^{3} \cdot {c}^{4}\right)}{{b}^{6}}}}{b}\right) - \frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}} \]
  9. Final simplification96.9%

    \[\leadsto \left(\mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{\frac{-5 \cdot \left({a}^{3} \cdot {c}^{4}\right)}{{b}^{6}}}{b}\right) - \frac{c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}} \]

Alternative 2: 94.1% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(0.03125, \frac{{c}^{3} \cdot -64}{\frac{{b}^{5}}{a \cdot a}}, \frac{-0.0625}{\frac{{b}^{3}}{a \cdot \left(\left(c \cdot c\right) \cdot 16\right)}}\right) - \frac{c}{b} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (-
  (fma
   0.03125
   (/ (* (pow c 3.0) -64.0) (/ (pow b 5.0) (* a a)))
   (/ -0.0625 (/ (pow b 3.0) (* a (* (* c c) 16.0)))))
  (/ c b)))
double code(double a, double b, double c) {
	return fma(0.03125, ((pow(c, 3.0) * -64.0) / (pow(b, 5.0) / (a * a))), (-0.0625 / (pow(b, 3.0) / (a * ((c * c) * 16.0))))) - (c / b);
}
function code(a, b, c)
	return Float64(fma(0.03125, Float64(Float64((c ^ 3.0) * -64.0) / Float64((b ^ 5.0) / Float64(a * a))), Float64(-0.0625 / Float64((b ^ 3.0) / Float64(a * Float64(Float64(c * c) * 16.0))))) - Float64(c / b))
end
code[a_, b_, c_] := N[(N[(0.03125 * N[(N[(N[Power[c, 3.0], $MachinePrecision] * -64.0), $MachinePrecision] / N[(N[Power[b, 5.0], $MachinePrecision] / N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-0.0625 / N[(N[Power[b, 3.0], $MachinePrecision] / N[(a * N[(N[(c * c), $MachinePrecision] * 16.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(0.03125, \frac{{c}^{3} \cdot -64}{\frac{{b}^{5}}{a \cdot a}}, \frac{-0.0625}{\frac{{b}^{3}}{a \cdot \left(\left(c \cdot c\right) \cdot 16\right)}}\right) - \frac{c}{b}
\end{array}
Derivation
  1. Initial program 28.1%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative28.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
    2. +-commutative28.1%

      \[\leadsto \frac{\color{blue}{\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c} + \left(-b\right)}}{a \cdot 2} \]
    3. unsub-neg28.1%

      \[\leadsto \frac{\color{blue}{\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c} - b}}{a \cdot 2} \]
    4. fma-neg28.1%

      \[\leadsto \frac{\sqrt{\color{blue}{\mathsf{fma}\left(b, b, -\left(4 \cdot a\right) \cdot c\right)}} - b}{a \cdot 2} \]
    5. associate-*l*28.1%

      \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{4 \cdot \left(a \cdot c\right)}\right)} - b}{a \cdot 2} \]
    6. *-commutative28.1%

      \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(a \cdot c\right) \cdot 4}\right)} - b}{a \cdot 2} \]
    7. distribute-rgt-neg-in28.1%

      \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot \left(-4\right)}\right)} - b}{a \cdot 2} \]
    8. metadata-eval28.1%

      \[\leadsto \frac{\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot \color{blue}{-4}\right)} - b}{a \cdot 2} \]
  3. Simplified28.1%

    \[\leadsto \color{blue}{\frac{\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b}{a \cdot 2}} \]
  4. Step-by-step derivation
    1. fma-udef28.1%

      \[\leadsto \frac{\sqrt{\color{blue}{b \cdot b + \left(a \cdot c\right) \cdot -4}} - b}{a \cdot 2} \]
    2. *-commutative28.1%

      \[\leadsto \frac{\sqrt{b \cdot b + \color{blue}{-4 \cdot \left(a \cdot c\right)}} - b}{a \cdot 2} \]
    3. metadata-eval28.1%

      \[\leadsto \frac{\sqrt{b \cdot b + \color{blue}{\left(-4\right)} \cdot \left(a \cdot c\right)} - b}{a \cdot 2} \]
    4. cancel-sign-sub-inv28.1%

      \[\leadsto \frac{\sqrt{\color{blue}{b \cdot b - 4 \cdot \left(a \cdot c\right)}} - b}{a \cdot 2} \]
    5. associate-*l*28.1%

      \[\leadsto \frac{\sqrt{b \cdot b - \color{blue}{\left(4 \cdot a\right) \cdot c}} - b}{a \cdot 2} \]
    6. *-un-lft-identity28.1%

      \[\leadsto \frac{\sqrt{b \cdot b - \color{blue}{1 \cdot \left(\left(4 \cdot a\right) \cdot c\right)}} - b}{a \cdot 2} \]
    7. prod-diff28.1%

      \[\leadsto \frac{\sqrt{\color{blue}{\mathsf{fma}\left(b, b, -\left(\left(4 \cdot a\right) \cdot c\right) \cdot 1\right) + \mathsf{fma}\left(-\left(4 \cdot a\right) \cdot c, 1, \left(\left(4 \cdot a\right) \cdot c\right) \cdot 1\right)}} - b}{a \cdot 2} \]
  5. Applied egg-rr28.1%

    \[\leadsto \frac{\sqrt{\color{blue}{\mathsf{fma}\left(b, b, -\left(a \cdot \left(c \cdot -4\right)\right) \cdot 1\right) + \mathsf{fma}\left(a \cdot \left(c \cdot -4\right), 1, \left(a \cdot \left(c \cdot -4\right)\right) \cdot 1\right)}} - b}{a \cdot 2} \]
  6. Taylor expanded in a around 0 95.7%

    \[\leadsto \color{blue}{0.25 \cdot \frac{-8 \cdot c - -4 \cdot c}{b} + \left(-0.0625 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{2} \cdot a}{{b}^{3}} + 0.03125 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{3} \cdot {a}^{2}}{{b}^{5}}\right)} \]
  7. Step-by-step derivation
    1. associate-*r/95.7%

      \[\leadsto \color{blue}{\frac{0.25 \cdot \left(-8 \cdot c - -4 \cdot c\right)}{b}} + \left(-0.0625 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{2} \cdot a}{{b}^{3}} + 0.03125 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{3} \cdot {a}^{2}}{{b}^{5}}\right) \]
    2. distribute-rgt-out--95.7%

      \[\leadsto \frac{0.25 \cdot \color{blue}{\left(c \cdot \left(-8 - -4\right)\right)}}{b} + \left(-0.0625 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{2} \cdot a}{{b}^{3}} + 0.03125 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{3} \cdot {a}^{2}}{{b}^{5}}\right) \]
    3. metadata-eval95.7%

      \[\leadsto \frac{0.25 \cdot \left(c \cdot \color{blue}{-4}\right)}{b} + \left(-0.0625 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{2} \cdot a}{{b}^{3}} + 0.03125 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{3} \cdot {a}^{2}}{{b}^{5}}\right) \]
    4. *-commutative95.7%

      \[\leadsto \frac{0.25 \cdot \color{blue}{\left(-4 \cdot c\right)}}{b} + \left(-0.0625 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{2} \cdot a}{{b}^{3}} + 0.03125 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{3} \cdot {a}^{2}}{{b}^{5}}\right) \]
    5. associate-*r*95.7%

      \[\leadsto \frac{\color{blue}{\left(0.25 \cdot -4\right) \cdot c}}{b} + \left(-0.0625 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{2} \cdot a}{{b}^{3}} + 0.03125 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{3} \cdot {a}^{2}}{{b}^{5}}\right) \]
    6. metadata-eval95.7%

      \[\leadsto \frac{\color{blue}{-1} \cdot c}{b} + \left(-0.0625 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{2} \cdot a}{{b}^{3}} + 0.03125 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{3} \cdot {a}^{2}}{{b}^{5}}\right) \]
    7. neg-mul-195.7%

      \[\leadsto \frac{\color{blue}{-c}}{b} + \left(-0.0625 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{2} \cdot a}{{b}^{3}} + 0.03125 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{3} \cdot {a}^{2}}{{b}^{5}}\right) \]
    8. +-commutative95.7%

      \[\leadsto \frac{-c}{b} + \color{blue}{\left(0.03125 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{3} \cdot {a}^{2}}{{b}^{5}} + -0.0625 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{2} \cdot a}{{b}^{3}}\right)} \]
    9. fma-def95.7%

      \[\leadsto \frac{-c}{b} + \color{blue}{\mathsf{fma}\left(0.03125, \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{3} \cdot {a}^{2}}{{b}^{5}}, -0.0625 \cdot \frac{{\left(-8 \cdot c - -4 \cdot c\right)}^{2} \cdot a}{{b}^{3}}\right)} \]
  8. Simplified95.7%

    \[\leadsto \color{blue}{\frac{-c}{b} + \mathsf{fma}\left(0.03125, \frac{{c}^{3} \cdot -64}{\frac{{b}^{5}}{a \cdot a}}, \frac{-0.0625}{\frac{{b}^{3}}{a \cdot \left(\left(c \cdot c\right) \cdot 16\right)}}\right)} \]
  9. Final simplification95.7%

    \[\leadsto \mathsf{fma}\left(0.03125, \frac{{c}^{3} \cdot -64}{\frac{{b}^{5}}{a \cdot a}}, \frac{-0.0625}{\frac{{b}^{3}}{a \cdot \left(\left(c \cdot c\right) \cdot 16\right)}}\right) - \frac{c}{b} \]

Alternative 3: 94.1% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{-c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (-
  (fma -2.0 (/ (pow c 3.0) (/ (pow b 5.0) (* a a))) (/ (- c) b))
  (/ (* c c) (/ (pow b 3.0) a))))
double code(double a, double b, double c) {
	return fma(-2.0, (pow(c, 3.0) / (pow(b, 5.0) / (a * a))), (-c / b)) - ((c * c) / (pow(b, 3.0) / a));
}
function code(a, b, c)
	return Float64(fma(-2.0, Float64((c ^ 3.0) / Float64((b ^ 5.0) / Float64(a * a))), Float64(Float64(-c) / b)) - Float64(Float64(c * c) / Float64((b ^ 3.0) / a)))
end
code[a_, b_, c_] := N[(N[(-2.0 * N[(N[Power[c, 3.0], $MachinePrecision] / N[(N[Power[b, 5.0], $MachinePrecision] / N[(a * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[((-c) / b), $MachinePrecision]), $MachinePrecision] - N[(N[(c * c), $MachinePrecision] / N[(N[Power[b, 3.0], $MachinePrecision] / a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{-c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}}
\end{array}
Derivation
  1. Initial program 28.1%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. /-rgt-identity28.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{\frac{2 \cdot a}{1}}} \]
    2. metadata-eval28.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\frac{2 \cdot a}{\color{blue}{--1}}} \]
    3. associate-/l*28.1%

      \[\leadsto \color{blue}{\frac{\left(\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\right) \cdot \left(--1\right)}{2 \cdot a}} \]
    4. associate-*r/28.1%

      \[\leadsto \color{blue}{\left(\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\right) \cdot \frac{--1}{2 \cdot a}} \]
    5. +-commutative28.1%

      \[\leadsto \color{blue}{\left(\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c} + \left(-b\right)\right)} \cdot \frac{--1}{2 \cdot a} \]
    6. unsub-neg28.1%

      \[\leadsto \color{blue}{\left(\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c} - b\right)} \cdot \frac{--1}{2 \cdot a} \]
    7. fma-neg28.1%

      \[\leadsto \left(\sqrt{\color{blue}{\mathsf{fma}\left(b, b, -\left(4 \cdot a\right) \cdot c\right)}} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    8. associate-*l*28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{4 \cdot \left(a \cdot c\right)}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    9. *-commutative28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(a \cdot c\right) \cdot 4}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    10. distribute-rgt-neg-in28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot \left(-4\right)}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    11. metadata-eval28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot \color{blue}{-4}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    12. associate-/r*28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \color{blue}{\frac{\frac{--1}{2}}{a}} \]
    13. metadata-eval28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{\frac{\color{blue}{1}}{2}}{a} \]
    14. metadata-eval28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{\color{blue}{0.5}}{a} \]
  3. Simplified28.1%

    \[\leadsto \color{blue}{\left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{0.5}{a}} \]
  4. Taylor expanded in b around inf 95.7%

    \[\leadsto \color{blue}{-1 \cdot \frac{{c}^{2} \cdot a}{{b}^{3}} + \left(-1 \cdot \frac{c}{b} + -2 \cdot \frac{{c}^{3} \cdot {a}^{2}}{{b}^{5}}\right)} \]
  5. Step-by-step derivation
    1. +-commutative95.7%

      \[\leadsto \color{blue}{\left(-1 \cdot \frac{c}{b} + -2 \cdot \frac{{c}^{3} \cdot {a}^{2}}{{b}^{5}}\right) + -1 \cdot \frac{{c}^{2} \cdot a}{{b}^{3}}} \]
    2. mul-1-neg95.7%

      \[\leadsto \left(-1 \cdot \frac{c}{b} + -2 \cdot \frac{{c}^{3} \cdot {a}^{2}}{{b}^{5}}\right) + \color{blue}{\left(-\frac{{c}^{2} \cdot a}{{b}^{3}}\right)} \]
    3. unsub-neg95.7%

      \[\leadsto \color{blue}{\left(-1 \cdot \frac{c}{b} + -2 \cdot \frac{{c}^{3} \cdot {a}^{2}}{{b}^{5}}\right) - \frac{{c}^{2} \cdot a}{{b}^{3}}} \]
    4. +-commutative95.7%

      \[\leadsto \color{blue}{\left(-2 \cdot \frac{{c}^{3} \cdot {a}^{2}}{{b}^{5}} + -1 \cdot \frac{c}{b}\right)} - \frac{{c}^{2} \cdot a}{{b}^{3}} \]
    5. fma-def95.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(-2, \frac{{c}^{3} \cdot {a}^{2}}{{b}^{5}}, -1 \cdot \frac{c}{b}\right)} - \frac{{c}^{2} \cdot a}{{b}^{3}} \]
    6. associate-/l*95.7%

      \[\leadsto \mathsf{fma}\left(-2, \color{blue}{\frac{{c}^{3}}{\frac{{b}^{5}}{{a}^{2}}}}, -1 \cdot \frac{c}{b}\right) - \frac{{c}^{2} \cdot a}{{b}^{3}} \]
    7. unpow295.7%

      \[\leadsto \mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{\color{blue}{a \cdot a}}}, -1 \cdot \frac{c}{b}\right) - \frac{{c}^{2} \cdot a}{{b}^{3}} \]
    8. mul-1-neg95.7%

      \[\leadsto \mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \color{blue}{-\frac{c}{b}}\right) - \frac{{c}^{2} \cdot a}{{b}^{3}} \]
    9. distribute-neg-frac95.7%

      \[\leadsto \mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \color{blue}{\frac{-c}{b}}\right) - \frac{{c}^{2} \cdot a}{{b}^{3}} \]
    10. associate-/l*95.7%

      \[\leadsto \mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{-c}{b}\right) - \color{blue}{\frac{{c}^{2}}{\frac{{b}^{3}}{a}}} \]
    11. unpow295.7%

      \[\leadsto \mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{-c}{b}\right) - \frac{\color{blue}{c \cdot c}}{\frac{{b}^{3}}{a}} \]
  6. Simplified95.7%

    \[\leadsto \color{blue}{\mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{-c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}}} \]
  7. Final simplification95.7%

    \[\leadsto \mathsf{fma}\left(-2, \frac{{c}^{3}}{\frac{{b}^{5}}{a \cdot a}}, \frac{-c}{b}\right) - \frac{c \cdot c}{\frac{{b}^{3}}{a}} \]

Alternative 4: 91.0% accurate, 1.0× speedup?

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

\\
\frac{-c}{b} - \frac{c \cdot c}{\frac{{b}^{3}}{a}}
\end{array}
Derivation
  1. Initial program 28.1%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. /-rgt-identity28.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{\frac{2 \cdot a}{1}}} \]
    2. metadata-eval28.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\frac{2 \cdot a}{\color{blue}{--1}}} \]
    3. associate-/l*28.1%

      \[\leadsto \color{blue}{\frac{\left(\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\right) \cdot \left(--1\right)}{2 \cdot a}} \]
    4. associate-*r/28.1%

      \[\leadsto \color{blue}{\left(\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\right) \cdot \frac{--1}{2 \cdot a}} \]
    5. +-commutative28.1%

      \[\leadsto \color{blue}{\left(\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c} + \left(-b\right)\right)} \cdot \frac{--1}{2 \cdot a} \]
    6. unsub-neg28.1%

      \[\leadsto \color{blue}{\left(\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c} - b\right)} \cdot \frac{--1}{2 \cdot a} \]
    7. fma-neg28.1%

      \[\leadsto \left(\sqrt{\color{blue}{\mathsf{fma}\left(b, b, -\left(4 \cdot a\right) \cdot c\right)}} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    8. associate-*l*28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{4 \cdot \left(a \cdot c\right)}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    9. *-commutative28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(a \cdot c\right) \cdot 4}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    10. distribute-rgt-neg-in28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot \left(-4\right)}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    11. metadata-eval28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot \color{blue}{-4}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    12. associate-/r*28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \color{blue}{\frac{\frac{--1}{2}}{a}} \]
    13. metadata-eval28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{\frac{\color{blue}{1}}{2}}{a} \]
    14. metadata-eval28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{\color{blue}{0.5}}{a} \]
  3. Simplified28.1%

    \[\leadsto \color{blue}{\left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{0.5}{a}} \]
  4. Taylor expanded in b around inf 93.1%

    \[\leadsto \color{blue}{-1 \cdot \frac{{c}^{2} \cdot a}{{b}^{3}} + -1 \cdot \frac{c}{b}} \]
  5. Step-by-step derivation
    1. +-commutative93.1%

      \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} + -1 \cdot \frac{{c}^{2} \cdot a}{{b}^{3}}} \]
    2. mul-1-neg93.1%

      \[\leadsto -1 \cdot \frac{c}{b} + \color{blue}{\left(-\frac{{c}^{2} \cdot a}{{b}^{3}}\right)} \]
    3. unsub-neg93.1%

      \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} - \frac{{c}^{2} \cdot a}{{b}^{3}}} \]
    4. mul-1-neg93.1%

      \[\leadsto \color{blue}{\left(-\frac{c}{b}\right)} - \frac{{c}^{2} \cdot a}{{b}^{3}} \]
    5. distribute-neg-frac93.1%

      \[\leadsto \color{blue}{\frac{-c}{b}} - \frac{{c}^{2} \cdot a}{{b}^{3}} \]
    6. associate-/l*93.1%

      \[\leadsto \frac{-c}{b} - \color{blue}{\frac{{c}^{2}}{\frac{{b}^{3}}{a}}} \]
    7. unpow293.1%

      \[\leadsto \frac{-c}{b} - \frac{\color{blue}{c \cdot c}}{\frac{{b}^{3}}{a}} \]
  6. Simplified93.1%

    \[\leadsto \color{blue}{\frac{-c}{b} - \frac{c \cdot c}{\frac{{b}^{3}}{a}}} \]
  7. Final simplification93.1%

    \[\leadsto \frac{-c}{b} - \frac{c \cdot c}{\frac{{b}^{3}}{a}} \]

Alternative 5: 90.9% accurate, 5.5× speedup?

\[\begin{array}{l} \\ \frac{c \cdot \left(a \cdot -4\right)}{b + \left(b + -2 \cdot \left(a \cdot \frac{c}{b}\right)\right)} \cdot \frac{0.5}{a} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (* (/ (* c (* a -4.0)) (+ b (+ b (* -2.0 (* a (/ c b)))))) (/ 0.5 a)))
double code(double a, double b, double c) {
	return ((c * (a * -4.0)) / (b + (b + (-2.0 * (a * (c / b)))))) * (0.5 / 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 * (a * (-4.0d0))) / (b + (b + ((-2.0d0) * (a * (c / b)))))) * (0.5d0 / a)
end function
public static double code(double a, double b, double c) {
	return ((c * (a * -4.0)) / (b + (b + (-2.0 * (a * (c / b)))))) * (0.5 / a);
}
def code(a, b, c):
	return ((c * (a * -4.0)) / (b + (b + (-2.0 * (a * (c / b)))))) * (0.5 / a)
function code(a, b, c)
	return Float64(Float64(Float64(c * Float64(a * -4.0)) / Float64(b + Float64(b + Float64(-2.0 * Float64(a * Float64(c / b)))))) * Float64(0.5 / a))
end
function tmp = code(a, b, c)
	tmp = ((c * (a * -4.0)) / (b + (b + (-2.0 * (a * (c / b)))))) * (0.5 / a);
end
code[a_, b_, c_] := N[(N[(N[(c * N[(a * -4.0), $MachinePrecision]), $MachinePrecision] / N[(b + N[(b + N[(-2.0 * N[(a * N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(0.5 / a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{c \cdot \left(a \cdot -4\right)}{b + \left(b + -2 \cdot \left(a \cdot \frac{c}{b}\right)\right)} \cdot \frac{0.5}{a}
\end{array}
Derivation
  1. Initial program 28.1%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. /-rgt-identity28.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{\frac{2 \cdot a}{1}}} \]
    2. metadata-eval28.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\frac{2 \cdot a}{\color{blue}{--1}}} \]
    3. associate-/l*28.1%

      \[\leadsto \color{blue}{\frac{\left(\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\right) \cdot \left(--1\right)}{2 \cdot a}} \]
    4. associate-*r/28.1%

      \[\leadsto \color{blue}{\left(\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\right) \cdot \frac{--1}{2 \cdot a}} \]
    5. +-commutative28.1%

      \[\leadsto \color{blue}{\left(\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c} + \left(-b\right)\right)} \cdot \frac{--1}{2 \cdot a} \]
    6. unsub-neg28.1%

      \[\leadsto \color{blue}{\left(\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c} - b\right)} \cdot \frac{--1}{2 \cdot a} \]
    7. fma-neg28.1%

      \[\leadsto \left(\sqrt{\color{blue}{\mathsf{fma}\left(b, b, -\left(4 \cdot a\right) \cdot c\right)}} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    8. associate-*l*28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{4 \cdot \left(a \cdot c\right)}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    9. *-commutative28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(a \cdot c\right) \cdot 4}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    10. distribute-rgt-neg-in28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot \left(-4\right)}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    11. metadata-eval28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot \color{blue}{-4}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    12. associate-/r*28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \color{blue}{\frac{\frac{--1}{2}}{a}} \]
    13. metadata-eval28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{\frac{\color{blue}{1}}{2}}{a} \]
    14. metadata-eval28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{\color{blue}{0.5}}{a} \]
  3. Simplified28.1%

    \[\leadsto \color{blue}{\left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{0.5}{a}} \]
  4. Taylor expanded in b around inf 20.8%

    \[\leadsto \left(\color{blue}{\left(b + -2 \cdot \frac{c \cdot a}{b}\right)} - b\right) \cdot \frac{0.5}{a} \]
  5. Step-by-step derivation
    1. associate-*r/20.8%

      \[\leadsto \left(\left(b + \color{blue}{\frac{-2 \cdot \left(c \cdot a\right)}{b}}\right) - b\right) \cdot \frac{0.5}{a} \]
  6. Simplified20.8%

    \[\leadsto \left(\color{blue}{\left(b + \frac{-2 \cdot \left(c \cdot a\right)}{b}\right)} - b\right) \cdot \frac{0.5}{a} \]
  7. Step-by-step derivation
    1. flip--20.8%

      \[\leadsto \color{blue}{\frac{\left(b + \frac{-2 \cdot \left(c \cdot a\right)}{b}\right) \cdot \left(b + \frac{-2 \cdot \left(c \cdot a\right)}{b}\right) - b \cdot b}{\left(b + \frac{-2 \cdot \left(c \cdot a\right)}{b}\right) + b}} \cdot \frac{0.5}{a} \]
    2. associate-*r/20.8%

      \[\leadsto \frac{\left(b + \color{blue}{-2 \cdot \frac{c \cdot a}{b}}\right) \cdot \left(b + \frac{-2 \cdot \left(c \cdot a\right)}{b}\right) - b \cdot b}{\left(b + \frac{-2 \cdot \left(c \cdot a\right)}{b}\right) + b} \cdot \frac{0.5}{a} \]
    3. associate-/l*20.8%

      \[\leadsto \frac{\left(b + -2 \cdot \color{blue}{\frac{c}{\frac{b}{a}}}\right) \cdot \left(b + \frac{-2 \cdot \left(c \cdot a\right)}{b}\right) - b \cdot b}{\left(b + \frac{-2 \cdot \left(c \cdot a\right)}{b}\right) + b} \cdot \frac{0.5}{a} \]
    4. associate-/r/20.8%

      \[\leadsto \frac{\left(b + -2 \cdot \color{blue}{\left(\frac{c}{b} \cdot a\right)}\right) \cdot \left(b + \frac{-2 \cdot \left(c \cdot a\right)}{b}\right) - b \cdot b}{\left(b + \frac{-2 \cdot \left(c \cdot a\right)}{b}\right) + b} \cdot \frac{0.5}{a} \]
    5. associate-*r/20.8%

      \[\leadsto \frac{\left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) \cdot \left(b + \color{blue}{-2 \cdot \frac{c \cdot a}{b}}\right) - b \cdot b}{\left(b + \frac{-2 \cdot \left(c \cdot a\right)}{b}\right) + b} \cdot \frac{0.5}{a} \]
    6. associate-/l*20.8%

      \[\leadsto \frac{\left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) \cdot \left(b + -2 \cdot \color{blue}{\frac{c}{\frac{b}{a}}}\right) - b \cdot b}{\left(b + \frac{-2 \cdot \left(c \cdot a\right)}{b}\right) + b} \cdot \frac{0.5}{a} \]
    7. associate-/r/20.8%

      \[\leadsto \frac{\left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) \cdot \left(b + -2 \cdot \color{blue}{\left(\frac{c}{b} \cdot a\right)}\right) - b \cdot b}{\left(b + \frac{-2 \cdot \left(c \cdot a\right)}{b}\right) + b} \cdot \frac{0.5}{a} \]
    8. associate-*r/20.8%

      \[\leadsto \frac{\left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) \cdot \left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) - b \cdot b}{\left(b + \color{blue}{-2 \cdot \frac{c \cdot a}{b}}\right) + b} \cdot \frac{0.5}{a} \]
    9. associate-/l*20.8%

      \[\leadsto \frac{\left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) \cdot \left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) - b \cdot b}{\left(b + -2 \cdot \color{blue}{\frac{c}{\frac{b}{a}}}\right) + b} \cdot \frac{0.5}{a} \]
    10. associate-/r/20.8%

      \[\leadsto \frac{\left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) \cdot \left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) - b \cdot b}{\left(b + -2 \cdot \color{blue}{\left(\frac{c}{b} \cdot a\right)}\right) + b} \cdot \frac{0.5}{a} \]
  8. Applied egg-rr20.8%

    \[\leadsto \color{blue}{\frac{\left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) \cdot \left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) - b \cdot b}{\left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) + b}} \cdot \frac{0.5}{a} \]
  9. Taylor expanded in b around inf 92.9%

    \[\leadsto \frac{\color{blue}{-4 \cdot \left(c \cdot a\right)}}{\left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) + b} \cdot \frac{0.5}{a} \]
  10. Step-by-step derivation
    1. *-commutative92.9%

      \[\leadsto \frac{-4 \cdot \color{blue}{\left(a \cdot c\right)}}{\left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) + b} \cdot \frac{0.5}{a} \]
    2. *-commutative92.9%

      \[\leadsto \frac{\color{blue}{\left(a \cdot c\right) \cdot -4}}{\left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) + b} \cdot \frac{0.5}{a} \]
    3. *-commutative92.9%

      \[\leadsto \frac{\color{blue}{\left(c \cdot a\right)} \cdot -4}{\left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) + b} \cdot \frac{0.5}{a} \]
    4. associate-*r*92.9%

      \[\leadsto \frac{\color{blue}{c \cdot \left(a \cdot -4\right)}}{\left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) + b} \cdot \frac{0.5}{a} \]
  11. Simplified92.9%

    \[\leadsto \frac{\color{blue}{c \cdot \left(a \cdot -4\right)}}{\left(b + -2 \cdot \left(\frac{c}{b} \cdot a\right)\right) + b} \cdot \frac{0.5}{a} \]
  12. Final simplification92.9%

    \[\leadsto \frac{c \cdot \left(a \cdot -4\right)}{b + \left(b + -2 \cdot \left(a \cdot \frac{c}{b}\right)\right)} \cdot \frac{0.5}{a} \]

Alternative 6: 81.3% 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(Float64(-c) / 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 28.1%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. /-rgt-identity28.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{\frac{2 \cdot a}{1}}} \]
    2. metadata-eval28.1%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\frac{2 \cdot a}{\color{blue}{--1}}} \]
    3. associate-/l*28.1%

      \[\leadsto \color{blue}{\frac{\left(\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\right) \cdot \left(--1\right)}{2 \cdot a}} \]
    4. associate-*r/28.1%

      \[\leadsto \color{blue}{\left(\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}\right) \cdot \frac{--1}{2 \cdot a}} \]
    5. +-commutative28.1%

      \[\leadsto \color{blue}{\left(\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c} + \left(-b\right)\right)} \cdot \frac{--1}{2 \cdot a} \]
    6. unsub-neg28.1%

      \[\leadsto \color{blue}{\left(\sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c} - b\right)} \cdot \frac{--1}{2 \cdot a} \]
    7. fma-neg28.1%

      \[\leadsto \left(\sqrt{\color{blue}{\mathsf{fma}\left(b, b, -\left(4 \cdot a\right) \cdot c\right)}} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    8. associate-*l*28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{4 \cdot \left(a \cdot c\right)}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    9. *-commutative28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, -\color{blue}{\left(a \cdot c\right) \cdot 4}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    10. distribute-rgt-neg-in28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \color{blue}{\left(a \cdot c\right) \cdot \left(-4\right)}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    11. metadata-eval28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot \color{blue}{-4}\right)} - b\right) \cdot \frac{--1}{2 \cdot a} \]
    12. associate-/r*28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \color{blue}{\frac{\frac{--1}{2}}{a}} \]
    13. metadata-eval28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{\frac{\color{blue}{1}}{2}}{a} \]
    14. metadata-eval28.1%

      \[\leadsto \left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{\color{blue}{0.5}}{a} \]
  3. Simplified28.1%

    \[\leadsto \color{blue}{\left(\sqrt{\mathsf{fma}\left(b, b, \left(a \cdot c\right) \cdot -4\right)} - b\right) \cdot \frac{0.5}{a}} \]
  4. Taylor expanded in b around inf 84.0%

    \[\leadsto \color{blue}{-1 \cdot \frac{c}{b}} \]
  5. Step-by-step derivation
    1. mul-1-neg84.0%

      \[\leadsto \color{blue}{-\frac{c}{b}} \]
    2. distribute-neg-frac84.0%

      \[\leadsto \color{blue}{\frac{-c}{b}} \]
  6. Simplified84.0%

    \[\leadsto \color{blue}{\frac{-c}{b}} \]
  7. Final simplification84.0%

    \[\leadsto \frac{-c}{b} \]

Reproduce

?
herbie shell --seed 2023208 
(FPCore (a b c)
  :name "Quadratic roots, medium range"
  :precision binary64
  :pre (and (and (and (< 1.1102230246251565e-16 a) (< a 9007199254740992.0)) (and (< 1.1102230246251565e-16 b) (< b 9007199254740992.0))) (and (< 1.1102230246251565e-16 c) (< c 9007199254740992.0)))
  (/ (+ (- b) (sqrt (- (* b b) (* (* 4.0 a) c)))) (* 2.0 a)))