Quadratic roots, medium range

Percentage Accurate: 31.3% → 95.7%
Time: 13.1s
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: 31.3% 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: 95.7% accurate, 0.2× speedup?

\[\begin{array}{l} \\ -2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(\left(-0.25 \cdot \left(\frac{{\left(a \cdot c\right)}^{4}}{a} \cdot \frac{20}{{b}^{7}}\right) - \frac{a \cdot {c}^{2}}{{b}^{3}}\right) - \frac{c}{b}\right) \end{array} \]
(FPCore (a b c)
 :precision binary64
 (+
  (* -2.0 (/ (* (pow a 2.0) (pow c 3.0)) (pow b 5.0)))
  (-
   (-
    (* -0.25 (* (/ (pow (* a c) 4.0) a) (/ 20.0 (pow b 7.0))))
    (/ (* a (pow c 2.0)) (pow b 3.0)))
   (/ c b))))
double code(double a, double b, double c) {
	return (-2.0 * ((pow(a, 2.0) * pow(c, 3.0)) / pow(b, 5.0))) + (((-0.25 * ((pow((a * c), 4.0) / a) * (20.0 / pow(b, 7.0)))) - ((a * pow(c, 2.0)) / pow(b, 3.0))) - (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 = ((-2.0d0) * (((a ** 2.0d0) * (c ** 3.0d0)) / (b ** 5.0d0))) + ((((-0.25d0) * ((((a * c) ** 4.0d0) / a) * (20.0d0 / (b ** 7.0d0)))) - ((a * (c ** 2.0d0)) / (b ** 3.0d0))) - (c / b))
end function
public static double code(double a, double b, double c) {
	return (-2.0 * ((Math.pow(a, 2.0) * Math.pow(c, 3.0)) / Math.pow(b, 5.0))) + (((-0.25 * ((Math.pow((a * c), 4.0) / a) * (20.0 / Math.pow(b, 7.0)))) - ((a * Math.pow(c, 2.0)) / Math.pow(b, 3.0))) - (c / b));
}
def code(a, b, c):
	return (-2.0 * ((math.pow(a, 2.0) * math.pow(c, 3.0)) / math.pow(b, 5.0))) + (((-0.25 * ((math.pow((a * c), 4.0) / a) * (20.0 / math.pow(b, 7.0)))) - ((a * math.pow(c, 2.0)) / math.pow(b, 3.0))) - (c / b))
function code(a, b, c)
	return Float64(Float64(-2.0 * Float64(Float64((a ^ 2.0) * (c ^ 3.0)) / (b ^ 5.0))) + Float64(Float64(Float64(-0.25 * Float64(Float64((Float64(a * c) ^ 4.0) / a) * Float64(20.0 / (b ^ 7.0)))) - Float64(Float64(a * (c ^ 2.0)) / (b ^ 3.0))) - Float64(c / b)))
end
function tmp = code(a, b, c)
	tmp = (-2.0 * (((a ^ 2.0) * (c ^ 3.0)) / (b ^ 5.0))) + (((-0.25 * ((((a * c) ^ 4.0) / a) * (20.0 / (b ^ 7.0)))) - ((a * (c ^ 2.0)) / (b ^ 3.0))) - (c / b));
end
code[a_, b_, c_] := N[(N[(-2.0 * N[(N[(N[Power[a, 2.0], $MachinePrecision] * N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(N[(N[(-0.25 * N[(N[(N[Power[N[(a * c), $MachinePrecision], 4.0], $MachinePrecision] / a), $MachinePrecision] * N[(20.0 / N[Power[b, 7.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(N[(a * N[Power[c, 2.0], $MachinePrecision]), $MachinePrecision] / N[Power[b, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
-2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(\left(-0.25 \cdot \left(\frac{{\left(a \cdot c\right)}^{4}}{a} \cdot \frac{20}{{b}^{7}}\right) - \frac{a \cdot {c}^{2}}{{b}^{3}}\right) - \frac{c}{b}\right)
\end{array}
Derivation
  1. Initial program 28.9%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative28.9%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified28.9%

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

    \[\leadsto \color{blue}{-2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(-1 \cdot \frac{c}{b} + \left(-1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + -0.25 \cdot \frac{16 \cdot \left({a}^{4} \cdot {c}^{4}\right) + {\left(-2 \cdot \left({a}^{2} \cdot {c}^{2}\right)\right)}^{2}}{a \cdot {b}^{7}}\right)\right)} \]
  5. Step-by-step derivation
    1. *-commutative97.2%

      \[\leadsto -2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(-1 \cdot \frac{c}{b} + \left(-1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + -0.25 \cdot \frac{16 \cdot \left({a}^{4} \cdot {c}^{4}\right) + {\color{blue}{\left(\left({a}^{2} \cdot {c}^{2}\right) \cdot -2\right)}}^{2}}{a \cdot {b}^{7}}\right)\right) \]
    2. unpow-prod-down97.2%

      \[\leadsto -2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(-1 \cdot \frac{c}{b} + \left(-1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + -0.25 \cdot \frac{16 \cdot \left({a}^{4} \cdot {c}^{4}\right) + \color{blue}{{\left({a}^{2} \cdot {c}^{2}\right)}^{2} \cdot {-2}^{2}}}{a \cdot {b}^{7}}\right)\right) \]
    3. pow-prod-down97.2%

      \[\leadsto -2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(-1 \cdot \frac{c}{b} + \left(-1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + -0.25 \cdot \frac{16 \cdot \left({a}^{4} \cdot {c}^{4}\right) + {\color{blue}{\left({\left(a \cdot c\right)}^{2}\right)}}^{2} \cdot {-2}^{2}}{a \cdot {b}^{7}}\right)\right) \]
    4. pow-pow97.2%

      \[\leadsto -2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(-1 \cdot \frac{c}{b} + \left(-1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + -0.25 \cdot \frac{16 \cdot \left({a}^{4} \cdot {c}^{4}\right) + \color{blue}{{\left(a \cdot c\right)}^{\left(2 \cdot 2\right)}} \cdot {-2}^{2}}{a \cdot {b}^{7}}\right)\right) \]
    5. metadata-eval97.2%

      \[\leadsto -2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(-1 \cdot \frac{c}{b} + \left(-1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + -0.25 \cdot \frac{16 \cdot \left({a}^{4} \cdot {c}^{4}\right) + {\left(a \cdot c\right)}^{\color{blue}{4}} \cdot {-2}^{2}}{a \cdot {b}^{7}}\right)\right) \]
    6. metadata-eval97.2%

      \[\leadsto -2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(-1 \cdot \frac{c}{b} + \left(-1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + -0.25 \cdot \frac{16 \cdot \left({a}^{4} \cdot {c}^{4}\right) + {\left(a \cdot c\right)}^{4} \cdot \color{blue}{4}}{a \cdot {b}^{7}}\right)\right) \]
  6. Applied egg-rr97.2%

    \[\leadsto -2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(-1 \cdot \frac{c}{b} + \left(-1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + -0.25 \cdot \frac{16 \cdot \left({a}^{4} \cdot {c}^{4}\right) + \color{blue}{{\left(a \cdot c\right)}^{4} \cdot 4}}{a \cdot {b}^{7}}\right)\right) \]
  7. Taylor expanded in c around 0 97.2%

    \[\leadsto -2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(-1 \cdot \frac{c}{b} + \left(-1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + -0.25 \cdot \color{blue}{\frac{{c}^{4} \cdot \left(4 \cdot {a}^{4} + 16 \cdot {a}^{4}\right)}{a \cdot {b}^{7}}}\right)\right) \]
  8. Step-by-step derivation
    1. distribute-rgt-out97.2%

      \[\leadsto -2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(-1 \cdot \frac{c}{b} + \left(-1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + -0.25 \cdot \frac{{c}^{4} \cdot \color{blue}{\left({a}^{4} \cdot \left(4 + 16\right)\right)}}{a \cdot {b}^{7}}\right)\right) \]
    2. associate-*r*97.2%

      \[\leadsto -2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(-1 \cdot \frac{c}{b} + \left(-1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + -0.25 \cdot \frac{\color{blue}{\left({c}^{4} \cdot {a}^{4}\right) \cdot \left(4 + 16\right)}}{a \cdot {b}^{7}}\right)\right) \]
    3. *-commutative97.2%

      \[\leadsto -2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(-1 \cdot \frac{c}{b} + \left(-1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + -0.25 \cdot \frac{\color{blue}{\left({a}^{4} \cdot {c}^{4}\right)} \cdot \left(4 + 16\right)}{a \cdot {b}^{7}}\right)\right) \]
    4. times-frac97.2%

      \[\leadsto -2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(-1 \cdot \frac{c}{b} + \left(-1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + -0.25 \cdot \color{blue}{\left(\frac{{a}^{4} \cdot {c}^{4}}{a} \cdot \frac{4 + 16}{{b}^{7}}\right)}\right)\right) \]
  9. Simplified97.2%

    \[\leadsto -2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(-1 \cdot \frac{c}{b} + \left(-1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}} + -0.25 \cdot \color{blue}{\left(\frac{{\left(a \cdot c\right)}^{4}}{a} \cdot \frac{20}{{b}^{7}}\right)}\right)\right) \]
  10. Final simplification97.2%

    \[\leadsto -2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(\left(-0.25 \cdot \left(\frac{{\left(a \cdot c\right)}^{4}}{a} \cdot \frac{20}{{b}^{7}}\right) - \frac{a \cdot {c}^{2}}{{b}^{3}}\right) - \frac{c}{b}\right) \]

Alternative 2: 94.2% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \left(\frac{-2 \cdot \left({a}^{2} \cdot {c}^{3}\right)}{{b}^{5}} - \frac{c}{b}\right) - \frac{a}{\frac{{b}^{3}}{{c}^{2}}} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (-
  (- (/ (* -2.0 (* (pow a 2.0) (pow c 3.0))) (pow b 5.0)) (/ c b))
  (/ a (/ (pow b 3.0) (pow c 2.0)))))
double code(double a, double b, double c) {
	return (((-2.0 * (pow(a, 2.0) * pow(c, 3.0))) / pow(b, 5.0)) - (c / b)) - (a / (pow(b, 3.0) / pow(c, 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 = ((((-2.0d0) * ((a ** 2.0d0) * (c ** 3.0d0))) / (b ** 5.0d0)) - (c / b)) - (a / ((b ** 3.0d0) / (c ** 2.0d0)))
end function
public static double code(double a, double b, double c) {
	return (((-2.0 * (Math.pow(a, 2.0) * Math.pow(c, 3.0))) / Math.pow(b, 5.0)) - (c / b)) - (a / (Math.pow(b, 3.0) / Math.pow(c, 2.0)));
}
def code(a, b, c):
	return (((-2.0 * (math.pow(a, 2.0) * math.pow(c, 3.0))) / math.pow(b, 5.0)) - (c / b)) - (a / (math.pow(b, 3.0) / math.pow(c, 2.0)))
function code(a, b, c)
	return Float64(Float64(Float64(Float64(-2.0 * Float64((a ^ 2.0) * (c ^ 3.0))) / (b ^ 5.0)) - Float64(c / b)) - Float64(a / Float64((b ^ 3.0) / (c ^ 2.0))))
end
function tmp = code(a, b, c)
	tmp = (((-2.0 * ((a ^ 2.0) * (c ^ 3.0))) / (b ^ 5.0)) - (c / b)) - (a / ((b ^ 3.0) / (c ^ 2.0)));
end
code[a_, b_, c_] := N[(N[(N[(N[(-2.0 * N[(N[Power[a, 2.0], $MachinePrecision] * N[Power[c, 3.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / N[Power[b, 5.0], $MachinePrecision]), $MachinePrecision] - N[(c / b), $MachinePrecision]), $MachinePrecision] - N[(a / N[(N[Power[b, 3.0], $MachinePrecision] / N[Power[c, 2.0], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(\frac{-2 \cdot \left({a}^{2} \cdot {c}^{3}\right)}{{b}^{5}} - \frac{c}{b}\right) - \frac{a}{\frac{{b}^{3}}{{c}^{2}}}
\end{array}
Derivation
  1. Initial program 28.9%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative28.9%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified28.9%

    \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
  4. Taylor expanded in b around inf 96.0%

    \[\leadsto \color{blue}{-2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \left(-1 \cdot \frac{c}{b} + -1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}}\right)} \]
  5. Step-by-step derivation
    1. associate-+r+96.0%

      \[\leadsto \color{blue}{\left(-2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + -1 \cdot \frac{c}{b}\right) + -1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}}} \]
    2. mul-1-neg96.0%

      \[\leadsto \left(-2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + -1 \cdot \frac{c}{b}\right) + \color{blue}{\left(-\frac{a \cdot {c}^{2}}{{b}^{3}}\right)} \]
    3. unsub-neg96.0%

      \[\leadsto \color{blue}{\left(-2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + -1 \cdot \frac{c}{b}\right) - \frac{a \cdot {c}^{2}}{{b}^{3}}} \]
    4. mul-1-neg96.0%

      \[\leadsto \left(-2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} + \color{blue}{\left(-\frac{c}{b}\right)}\right) - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
    5. unsub-neg96.0%

      \[\leadsto \color{blue}{\left(-2 \cdot \frac{{a}^{2} \cdot {c}^{3}}{{b}^{5}} - \frac{c}{b}\right)} - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
    6. associate-*r/96.0%

      \[\leadsto \left(\color{blue}{\frac{-2 \cdot \left({a}^{2} \cdot {c}^{3}\right)}{{b}^{5}}} - \frac{c}{b}\right) - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
    7. *-commutative96.0%

      \[\leadsto \left(\frac{-2 \cdot \color{blue}{\left({c}^{3} \cdot {a}^{2}\right)}}{{b}^{5}} - \frac{c}{b}\right) - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
    8. associate-/l*96.0%

      \[\leadsto \left(\frac{-2 \cdot \left({c}^{3} \cdot {a}^{2}\right)}{{b}^{5}} - \frac{c}{b}\right) - \color{blue}{\frac{a}{\frac{{b}^{3}}{{c}^{2}}}} \]
  6. Simplified96.0%

    \[\leadsto \color{blue}{\left(\frac{-2 \cdot \left({c}^{3} \cdot {a}^{2}\right)}{{b}^{5}} - \frac{c}{b}\right) - \frac{a}{\frac{{b}^{3}}{{c}^{2}}}} \]
  7. Final simplification96.0%

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

Alternative 3: 84.1% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2}\\ \mathbf{if}\;t_0 \leq -8.5 \cdot 10^{-5}:\\ \;\;\;\;t_0\\ \mathbf{else}:\\ \;\;\;\;\frac{-c}{b}\\ \end{array} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (let* ((t_0 (/ (- (sqrt (- (* b b) (* c (* a 4.0)))) b) (* a 2.0))))
   (if (<= t_0 -8.5e-5) t_0 (/ (- c) b))))
double code(double a, double b, double c) {
	double t_0 = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
	double tmp;
	if (t_0 <= -8.5e-5) {
		tmp = t_0;
	} else {
		tmp = -c / b;
	}
	return tmp;
}
real(8) function code(a, b, c)
    real(8), intent (in) :: a
    real(8), intent (in) :: b
    real(8), intent (in) :: c
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (sqrt(((b * b) - (c * (a * 4.0d0)))) - b) / (a * 2.0d0)
    if (t_0 <= (-8.5d-5)) then
        tmp = t_0
    else
        tmp = -c / b
    end if
    code = tmp
end function
public static double code(double a, double b, double c) {
	double t_0 = (Math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
	double tmp;
	if (t_0 <= -8.5e-5) {
		tmp = t_0;
	} else {
		tmp = -c / b;
	}
	return tmp;
}
def code(a, b, c):
	t_0 = (math.sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0)
	tmp = 0
	if t_0 <= -8.5e-5:
		tmp = t_0
	else:
		tmp = -c / b
	return tmp
function code(a, b, c)
	t_0 = Float64(Float64(sqrt(Float64(Float64(b * b) - Float64(c * Float64(a * 4.0)))) - b) / Float64(a * 2.0))
	tmp = 0.0
	if (t_0 <= -8.5e-5)
		tmp = t_0;
	else
		tmp = Float64(Float64(-c) / b);
	end
	return tmp
end
function tmp_2 = code(a, b, c)
	t_0 = (sqrt(((b * b) - (c * (a * 4.0)))) - b) / (a * 2.0);
	tmp = 0.0;
	if (t_0 <= -8.5e-5)
		tmp = t_0;
	else
		tmp = -c / b;
	end
	tmp_2 = tmp;
end
code[a_, b_, c_] := Block[{t$95$0 = N[(N[(N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision] - b), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -8.5e-5], t$95$0, N[((-c) / b), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2}\\
\mathbf{if}\;t_0 \leq -8.5 \cdot 10^{-5}:\\
\;\;\;\;t_0\\

\mathbf{else}:\\
\;\;\;\;\frac{-c}{b}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c)))) (*.f64 2 a)) < -8.500000000000001e-5

    1. Initial program 71.0%

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

    if -8.500000000000001e-5 < (/.f64 (+.f64 (neg.f64 b) (sqrt.f64 (-.f64 (*.f64 b b) (*.f64 (*.f64 4 a) c)))) (*.f64 2 a))

    1. Initial program 18.7%

      \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
    2. Step-by-step derivation
      1. *-commutative18.7%

        \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
    3. Simplified18.7%

      \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
    4. Taylor expanded in b around inf 90.6%

      \[\leadsto \color{blue}{-1 \cdot \frac{c}{b}} \]
    5. Step-by-step derivation
      1. mul-1-neg90.6%

        \[\leadsto \color{blue}{-\frac{c}{b}} \]
      2. distribute-neg-frac90.6%

        \[\leadsto \color{blue}{\frac{-c}{b}} \]
    6. Simplified90.6%

      \[\leadsto \color{blue}{\frac{-c}{b}} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification86.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2} \leq -8.5 \cdot 10^{-5}:\\ \;\;\;\;\frac{\sqrt{b \cdot b - c \cdot \left(a \cdot 4\right)} - b}{a \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{-c}{b}\\ \end{array} \]

Alternative 4: 91.0% accurate, 0.5× speedup?

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

\\
\frac{-c}{b} - \frac{a}{\frac{{b}^{3}}{{c}^{2}}}
\end{array}
Derivation
  1. Initial program 28.9%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative28.9%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified28.9%

    \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
  4. Taylor expanded in b around inf 92.8%

    \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} + -1 \cdot \frac{a \cdot {c}^{2}}{{b}^{3}}} \]
  5. Step-by-step derivation
    1. mul-1-neg92.8%

      \[\leadsto -1 \cdot \frac{c}{b} + \color{blue}{\left(-\frac{a \cdot {c}^{2}}{{b}^{3}}\right)} \]
    2. unsub-neg92.8%

      \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} - \frac{a \cdot {c}^{2}}{{b}^{3}}} \]
    3. mul-1-neg92.8%

      \[\leadsto \color{blue}{\left(-\frac{c}{b}\right)} - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
    4. distribute-neg-frac92.8%

      \[\leadsto \color{blue}{\frac{-c}{b}} - \frac{a \cdot {c}^{2}}{{b}^{3}} \]
    5. associate-/l*92.8%

      \[\leadsto \frac{-c}{b} - \color{blue}{\frac{a}{\frac{{b}^{3}}{{c}^{2}}}} \]
  6. Simplified92.8%

    \[\leadsto \color{blue}{\frac{-c}{b} - \frac{a}{\frac{{b}^{3}}{{c}^{2}}}} \]
  7. Final simplification92.8%

    \[\leadsto \frac{-c}{b} - \frac{a}{\frac{{b}^{3}}{{c}^{2}}} \]

Alternative 5: 90.6% accurate, 0.9× speedup?

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

\\
\frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + \frac{1}{\frac{\frac{{b}^{3}}{a \cdot c}}{a \cdot c}}\right)}{a \cdot 2}
\end{array}
Derivation
  1. Initial program 28.9%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative28.9%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified28.9%

    \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
  4. Taylor expanded in b around inf 92.5%

    \[\leadsto \frac{\color{blue}{-2 \cdot \frac{a \cdot c}{b} + -2 \cdot \frac{{a}^{2} \cdot {c}^{2}}{{b}^{3}}}}{a \cdot 2} \]
  5. Step-by-step derivation
    1. *-un-lft-identity92.5%

      \[\leadsto \color{blue}{1 \cdot \frac{-2 \cdot \frac{a \cdot c}{b} + -2 \cdot \frac{{a}^{2} \cdot {c}^{2}}{{b}^{3}}}{a \cdot 2}} \]
  6. Applied egg-rr92.5%

    \[\leadsto \color{blue}{1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + {\left(\frac{a \cdot c}{{b}^{1.5}}\right)}^{2}\right)}{a \cdot 2}} \]
  7. Step-by-step derivation
    1. expm1-log1p-u92.5%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + {\color{blue}{\left(\mathsf{expm1}\left(\mathsf{log1p}\left(\frac{a \cdot c}{{b}^{1.5}}\right)\right)\right)}}^{2}\right)}{a \cdot 2} \]
    2. expm1-udef92.2%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + {\color{blue}{\left(e^{\mathsf{log1p}\left(\frac{a \cdot c}{{b}^{1.5}}\right)} - 1\right)}}^{2}\right)}{a \cdot 2} \]
    3. div-inv92.2%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + {\left(e^{\mathsf{log1p}\left(\color{blue}{\left(a \cdot c\right) \cdot \frac{1}{{b}^{1.5}}}\right)} - 1\right)}^{2}\right)}{a \cdot 2} \]
    4. pow-flip92.2%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + {\left(e^{\mathsf{log1p}\left(\left(a \cdot c\right) \cdot \color{blue}{{b}^{\left(-1.5\right)}}\right)} - 1\right)}^{2}\right)}{a \cdot 2} \]
    5. metadata-eval92.2%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + {\left(e^{\mathsf{log1p}\left(\left(a \cdot c\right) \cdot {b}^{\color{blue}{-1.5}}\right)} - 1\right)}^{2}\right)}{a \cdot 2} \]
  8. Applied egg-rr92.2%

    \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + {\color{blue}{\left(e^{\mathsf{log1p}\left(\left(a \cdot c\right) \cdot {b}^{-1.5}\right)} - 1\right)}}^{2}\right)}{a \cdot 2} \]
  9. Step-by-step derivation
    1. expm1-def92.5%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + {\color{blue}{\left(\mathsf{expm1}\left(\mathsf{log1p}\left(\left(a \cdot c\right) \cdot {b}^{-1.5}\right)\right)\right)}}^{2}\right)}{a \cdot 2} \]
    2. expm1-log1p-u92.5%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + {\color{blue}{\left(\left(a \cdot c\right) \cdot {b}^{-1.5}\right)}}^{2}\right)}{a \cdot 2} \]
    3. metadata-eval92.5%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + {\left(\left(a \cdot c\right) \cdot {b}^{\color{blue}{\left(-1.5\right)}}\right)}^{2}\right)}{a \cdot 2} \]
    4. pow-flip92.5%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + {\left(\left(a \cdot c\right) \cdot \color{blue}{\frac{1}{{b}^{1.5}}}\right)}^{2}\right)}{a \cdot 2} \]
    5. div-inv92.5%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + {\color{blue}{\left(\frac{a \cdot c}{{b}^{1.5}}\right)}}^{2}\right)}{a \cdot 2} \]
    6. unpow292.5%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + \color{blue}{\frac{a \cdot c}{{b}^{1.5}} \cdot \frac{a \cdot c}{{b}^{1.5}}}\right)}{a \cdot 2} \]
    7. clear-num92.5%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + \color{blue}{\frac{1}{\frac{{b}^{1.5}}{a \cdot c}}} \cdot \frac{a \cdot c}{{b}^{1.5}}\right)}{a \cdot 2} \]
    8. clear-num92.5%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + \frac{1}{\frac{{b}^{1.5}}{a \cdot c}} \cdot \color{blue}{\frac{1}{\frac{{b}^{1.5}}{a \cdot c}}}\right)}{a \cdot 2} \]
    9. frac-times92.5%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + \color{blue}{\frac{1 \cdot 1}{\frac{{b}^{1.5}}{a \cdot c} \cdot \frac{{b}^{1.5}}{a \cdot c}}}\right)}{a \cdot 2} \]
    10. metadata-eval92.5%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + \frac{\color{blue}{1}}{\frac{{b}^{1.5}}{a \cdot c} \cdot \frac{{b}^{1.5}}{a \cdot c}}\right)}{a \cdot 2} \]
  10. Applied egg-rr92.5%

    \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + \color{blue}{\frac{1}{\frac{{b}^{1.5}}{a \cdot c} \cdot \frac{{b}^{1.5}}{a \cdot c}}}\right)}{a \cdot 2} \]
  11. Step-by-step derivation
    1. associate-*r/92.5%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + \frac{1}{\color{blue}{\frac{\frac{{b}^{1.5}}{a \cdot c} \cdot {b}^{1.5}}{a \cdot c}}}\right)}{a \cdot 2} \]
    2. associate-*l/92.5%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + \frac{1}{\frac{\color{blue}{\frac{{b}^{1.5} \cdot {b}^{1.5}}{a \cdot c}}}{a \cdot c}}\right)}{a \cdot 2} \]
    3. pow-sqr92.5%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + \frac{1}{\frac{\frac{\color{blue}{{b}^{\left(2 \cdot 1.5\right)}}}{a \cdot c}}{a \cdot c}}\right)}{a \cdot 2} \]
    4. metadata-eval92.5%

      \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + \frac{1}{\frac{\frac{{b}^{\color{blue}{3}}}{a \cdot c}}{a \cdot c}}\right)}{a \cdot 2} \]
  12. Simplified92.5%

    \[\leadsto 1 \cdot \frac{-2 \cdot \left(\frac{a}{\frac{b}{c}} + \color{blue}{\frac{1}{\frac{\frac{{b}^{3}}{a \cdot c}}{a \cdot c}}}\right)}{a \cdot 2} \]
  13. Final simplification92.5%

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

Alternative 6: 81.5% 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 28.9%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Step-by-step derivation
    1. *-commutative28.9%

      \[\leadsto \frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{\color{blue}{a \cdot 2}} \]
  3. Simplified28.9%

    \[\leadsto \color{blue}{\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{a \cdot 2}} \]
  4. Taylor expanded in b around inf 83.1%

    \[\leadsto \color{blue}{-1 \cdot \frac{c}{b}} \]
  5. Step-by-step derivation
    1. mul-1-neg83.1%

      \[\leadsto \color{blue}{-\frac{c}{b}} \]
    2. distribute-neg-frac83.1%

      \[\leadsto \color{blue}{\frac{-c}{b}} \]
  6. Simplified83.1%

    \[\leadsto \color{blue}{\frac{-c}{b}} \]
  7. Final simplification83.1%

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

Reproduce

?
herbie shell --seed 2023332 
(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)))