Quadratic roots, medium range

Percentage Accurate: 31.6% → 99.4%
Time: 11.9s
Alternatives: 8
Speedup: 3.6×

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 8 alternatives:

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

Initial Program: 31.6% 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: 99.4% accurate, 0.3× speedup?

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

\\
{\left(\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}\right)}^{-1} \cdot \frac{c \cdot \left(a \cdot 4\right)}{2 \cdot a}
\end{array}
Derivation
  1. Initial program 32.4%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in a around inf

    \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{a \cdot \left(\frac{{b}^{2}}{a} - 4 \cdot c\right)}}}{2 \cdot a} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(\frac{{b}^{2}}{a} - 4 \cdot c\right) \cdot a}}}{2 \cdot a} \]
    2. lower-*.f64N/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(\frac{{b}^{2}}{a} - 4 \cdot c\right) \cdot a}}}{2 \cdot a} \]
    3. cancel-sign-sub-invN/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(\frac{{b}^{2}}{a} + \left(\mathsf{neg}\left(4\right)\right) \cdot c\right)} \cdot a}}{2 \cdot a} \]
    4. metadata-evalN/A

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

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(-4 \cdot c + \frac{{b}^{2}}{a}\right)} \cdot a}}{2 \cdot a} \]
    6. lower-fma.f64N/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(-4, c, \frac{{b}^{2}}{a}\right)} \cdot a}}{2 \cdot a} \]
    7. unpow2N/A

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

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, \color{blue}{b \cdot \frac{b}{a}}\right) \cdot a}}{2 \cdot a} \]
    9. lower-*.f64N/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, \color{blue}{b \cdot \frac{b}{a}}\right) \cdot a}}{2 \cdot a} \]
    10. lower-/.f6432.3

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, b \cdot \color{blue}{\frac{b}{a}}\right) \cdot a}}{2 \cdot a} \]
  5. Applied rewrites32.3%

    \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}{2 \cdot a} \]
  6. Step-by-step derivation
    1. lift-+.f64N/A

      \[\leadsto \frac{\color{blue}{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}{2 \cdot a} \]
    2. flip-+N/A

      \[\leadsto \frac{\color{blue}{\frac{\left(-b\right) \cdot \left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a} \cdot \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}}{2 \cdot a} \]
    3. clear-numN/A

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}{\left(-b\right) \cdot \left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a} \cdot \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}}}{2 \cdot a} \]
    4. lower-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}{\left(-b\right) \cdot \left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a} \cdot \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}}}{2 \cdot a} \]
  7. Applied rewrites32.9%

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

    \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{\color{blue}{4 \cdot \left(a \cdot c\right)}}}}{2 \cdot a} \]
  9. Step-by-step derivation
    1. lower-*.f64N/A

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{\color{blue}{4 \cdot \left(a \cdot c\right)}}}}{2 \cdot a} \]
    2. lower-*.f6499.3

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{4 \cdot \color{blue}{\left(a \cdot c\right)}}}}{2 \cdot a} \]
  10. Applied rewrites99.3%

    \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{\color{blue}{4 \cdot \left(a \cdot c\right)}}}}{2 \cdot a} \]
  11. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{4 \cdot \left(a \cdot c\right)}}}{2 \cdot a}} \]
    2. lift-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{4 \cdot \left(a \cdot c\right)}}}}{2 \cdot a} \]
    3. lift-/.f64N/A

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

      \[\leadsto \frac{\color{blue}{\frac{1}{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}} \cdot \left(4 \cdot \left(a \cdot c\right)\right)}}{2 \cdot a} \]
  12. Applied rewrites99.4%

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

Alternative 2: 99.3% accurate, 0.3× speedup?

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

\\
\frac{{\left(\frac{b + \sqrt{\mathsf{fma}\left(-4, c \cdot a, b \cdot b\right)}}{4 \cdot \left(a \cdot c\right)}\right)}^{-1}}{2 \cdot \left(-a\right)}
\end{array}
Derivation
  1. Initial program 32.4%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in a around inf

    \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{a \cdot \left(\frac{{b}^{2}}{a} - 4 \cdot c\right)}}}{2 \cdot a} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(\frac{{b}^{2}}{a} - 4 \cdot c\right) \cdot a}}}{2 \cdot a} \]
    2. lower-*.f64N/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(\frac{{b}^{2}}{a} - 4 \cdot c\right) \cdot a}}}{2 \cdot a} \]
    3. cancel-sign-sub-invN/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(\frac{{b}^{2}}{a} + \left(\mathsf{neg}\left(4\right)\right) \cdot c\right)} \cdot a}}{2 \cdot a} \]
    4. metadata-evalN/A

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

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(-4 \cdot c + \frac{{b}^{2}}{a}\right)} \cdot a}}{2 \cdot a} \]
    6. lower-fma.f64N/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(-4, c, \frac{{b}^{2}}{a}\right)} \cdot a}}{2 \cdot a} \]
    7. unpow2N/A

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

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, \color{blue}{b \cdot \frac{b}{a}}\right) \cdot a}}{2 \cdot a} \]
    9. lower-*.f64N/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, \color{blue}{b \cdot \frac{b}{a}}\right) \cdot a}}{2 \cdot a} \]
    10. lower-/.f6432.3

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, b \cdot \color{blue}{\frac{b}{a}}\right) \cdot a}}{2 \cdot a} \]
  5. Applied rewrites32.3%

    \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}{2 \cdot a} \]
  6. Step-by-step derivation
    1. lift-+.f64N/A

      \[\leadsto \frac{\color{blue}{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}{2 \cdot a} \]
    2. flip-+N/A

      \[\leadsto \frac{\color{blue}{\frac{\left(-b\right) \cdot \left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a} \cdot \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}}{2 \cdot a} \]
    3. clear-numN/A

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}{\left(-b\right) \cdot \left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a} \cdot \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}}}{2 \cdot a} \]
    4. lower-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}{\left(-b\right) \cdot \left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a} \cdot \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}}}{2 \cdot a} \]
  7. Applied rewrites32.9%

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

    \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{\color{blue}{4 \cdot \left(a \cdot c\right)}}}}{2 \cdot a} \]
  9. Step-by-step derivation
    1. lower-*.f64N/A

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{\color{blue}{4 \cdot \left(a \cdot c\right)}}}}{2 \cdot a} \]
    2. lower-*.f6499.3

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{4 \cdot \color{blue}{\left(a \cdot c\right)}}}}{2 \cdot a} \]
  10. Applied rewrites99.3%

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

    \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{{b}^{2} - 4 \cdot \left(a \cdot c\right)}}}{4 \cdot \left(a \cdot c\right)}}}{2 \cdot a} \]
  12. Step-by-step derivation
    1. cancel-sign-sub-invN/A

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{{b}^{2} + \left(\mathsf{neg}\left(4\right)\right) \cdot \left(a \cdot c\right)}}}{4 \cdot \left(a \cdot c\right)}}}{2 \cdot a} \]
    2. metadata-evalN/A

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

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\color{blue}{-4 \cdot \left(a \cdot c\right) + {b}^{2}}}}{4 \cdot \left(a \cdot c\right)}}}{2 \cdot a} \]
    4. lower-fma.f64N/A

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

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, \color{blue}{c \cdot a}, {b}^{2}\right)}}{4 \cdot \left(a \cdot c\right)}}}{2 \cdot a} \]
    6. lower-*.f64N/A

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, \color{blue}{c \cdot a}, {b}^{2}\right)}}{4 \cdot \left(a \cdot c\right)}}}{2 \cdot a} \]
    7. unpow2N/A

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, \color{blue}{b \cdot b}\right)}}{4 \cdot \left(a \cdot c\right)}}}{2 \cdot a} \]
    8. lower-*.f6499.4

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c \cdot a, \color{blue}{b \cdot b}\right)}}{4 \cdot \left(a \cdot c\right)}}}{2 \cdot a} \]
  13. Applied rewrites99.4%

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

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

Alternative 3: 90.8% accurate, 0.3× speedup?

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

\\
\frac{{\left(\frac{\mathsf{fma}\left(-0.5, \frac{b}{a}, 0.5 \cdot \frac{c}{b}\right)}{c}\right)}^{-1}}{2 \cdot a}
\end{array}
Derivation
  1. Initial program 32.4%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in a around inf

    \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{a \cdot \left(\frac{{b}^{2}}{a} - 4 \cdot c\right)}}}{2 \cdot a} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(\frac{{b}^{2}}{a} - 4 \cdot c\right) \cdot a}}}{2 \cdot a} \]
    2. lower-*.f64N/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(\frac{{b}^{2}}{a} - 4 \cdot c\right) \cdot a}}}{2 \cdot a} \]
    3. cancel-sign-sub-invN/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(\frac{{b}^{2}}{a} + \left(\mathsf{neg}\left(4\right)\right) \cdot c\right)} \cdot a}}{2 \cdot a} \]
    4. metadata-evalN/A

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

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(-4 \cdot c + \frac{{b}^{2}}{a}\right)} \cdot a}}{2 \cdot a} \]
    6. lower-fma.f64N/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(-4, c, \frac{{b}^{2}}{a}\right)} \cdot a}}{2 \cdot a} \]
    7. unpow2N/A

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

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, \color{blue}{b \cdot \frac{b}{a}}\right) \cdot a}}{2 \cdot a} \]
    9. lower-*.f64N/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, \color{blue}{b \cdot \frac{b}{a}}\right) \cdot a}}{2 \cdot a} \]
    10. lower-/.f6432.3

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, b \cdot \color{blue}{\frac{b}{a}}\right) \cdot a}}{2 \cdot a} \]
  5. Applied rewrites32.3%

    \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}{2 \cdot a} \]
  6. Step-by-step derivation
    1. lift-+.f64N/A

      \[\leadsto \frac{\color{blue}{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}{2 \cdot a} \]
    2. flip-+N/A

      \[\leadsto \frac{\color{blue}{\frac{\left(-b\right) \cdot \left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a} \cdot \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}}{2 \cdot a} \]
    3. clear-numN/A

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}{\left(-b\right) \cdot \left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a} \cdot \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}}}{2 \cdot a} \]
    4. lower-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}{\left(-b\right) \cdot \left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a} \cdot \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}}}{2 \cdot a} \]
  7. Applied rewrites32.9%

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

    \[\leadsto \frac{\frac{1}{\color{blue}{\frac{\frac{-1}{2} \cdot \frac{b}{a} + \frac{1}{2} \cdot \frac{c}{b}}{c}}}}{2 \cdot a} \]
  9. Step-by-step derivation
    1. lower-/.f64N/A

      \[\leadsto \frac{\frac{1}{\color{blue}{\frac{\frac{-1}{2} \cdot \frac{b}{a} + \frac{1}{2} \cdot \frac{c}{b}}{c}}}}{2 \cdot a} \]
    2. lower-fma.f64N/A

      \[\leadsto \frac{\frac{1}{\frac{\color{blue}{\mathsf{fma}\left(\frac{-1}{2}, \frac{b}{a}, \frac{1}{2} \cdot \frac{c}{b}\right)}}{c}}}{2 \cdot a} \]
    3. lower-/.f64N/A

      \[\leadsto \frac{\frac{1}{\frac{\mathsf{fma}\left(\frac{-1}{2}, \color{blue}{\frac{b}{a}}, \frac{1}{2} \cdot \frac{c}{b}\right)}{c}}}{2 \cdot a} \]
    4. lower-*.f64N/A

      \[\leadsto \frac{\frac{1}{\frac{\mathsf{fma}\left(\frac{-1}{2}, \frac{b}{a}, \color{blue}{\frac{1}{2} \cdot \frac{c}{b}}\right)}{c}}}{2 \cdot a} \]
    5. lower-/.f6489.7

      \[\leadsto \frac{\frac{1}{\frac{\mathsf{fma}\left(-0.5, \frac{b}{a}, 0.5 \cdot \color{blue}{\frac{c}{b}}\right)}{c}}}{2 \cdot a} \]
  10. Applied rewrites89.7%

    \[\leadsto \frac{\frac{1}{\color{blue}{\frac{\mathsf{fma}\left(-0.5, \frac{b}{a}, 0.5 \cdot \frac{c}{b}\right)}{c}}}}{2 \cdot a} \]
  11. Final simplification89.7%

    \[\leadsto \frac{{\left(\frac{\mathsf{fma}\left(-0.5, \frac{b}{a}, 0.5 \cdot \frac{c}{b}\right)}{c}\right)}^{-1}}{2 \cdot a} \]
  12. Add Preprocessing

Alternative 4: 99.3% accurate, 0.6× speedup?

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

\\
\frac{\frac{c \cdot \left(a \cdot 4\right)}{b + \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}}{2 \cdot \left(-a\right)}
\end{array}
Derivation
  1. Initial program 32.4%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in a around inf

    \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{a \cdot \left(\frac{{b}^{2}}{a} - 4 \cdot c\right)}}}{2 \cdot a} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(\frac{{b}^{2}}{a} - 4 \cdot c\right) \cdot a}}}{2 \cdot a} \]
    2. lower-*.f64N/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(\frac{{b}^{2}}{a} - 4 \cdot c\right) \cdot a}}}{2 \cdot a} \]
    3. cancel-sign-sub-invN/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(\frac{{b}^{2}}{a} + \left(\mathsf{neg}\left(4\right)\right) \cdot c\right)} \cdot a}}{2 \cdot a} \]
    4. metadata-evalN/A

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

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(-4 \cdot c + \frac{{b}^{2}}{a}\right)} \cdot a}}{2 \cdot a} \]
    6. lower-fma.f64N/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(-4, c, \frac{{b}^{2}}{a}\right)} \cdot a}}{2 \cdot a} \]
    7. unpow2N/A

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

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, \color{blue}{b \cdot \frac{b}{a}}\right) \cdot a}}{2 \cdot a} \]
    9. lower-*.f64N/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, \color{blue}{b \cdot \frac{b}{a}}\right) \cdot a}}{2 \cdot a} \]
    10. lower-/.f6432.3

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, b \cdot \color{blue}{\frac{b}{a}}\right) \cdot a}}{2 \cdot a} \]
  5. Applied rewrites32.3%

    \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}{2 \cdot a} \]
  6. Step-by-step derivation
    1. lift-+.f64N/A

      \[\leadsto \frac{\color{blue}{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}{2 \cdot a} \]
    2. flip-+N/A

      \[\leadsto \frac{\color{blue}{\frac{\left(-b\right) \cdot \left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a} \cdot \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}}{2 \cdot a} \]
    3. clear-numN/A

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}{\left(-b\right) \cdot \left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a} \cdot \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}}}{2 \cdot a} \]
    4. lower-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}{\left(-b\right) \cdot \left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a} \cdot \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}}}{2 \cdot a} \]
  7. Applied rewrites32.9%

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

    \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{\color{blue}{4 \cdot \left(a \cdot c\right)}}}}{2 \cdot a} \]
  9. Step-by-step derivation
    1. lower-*.f64N/A

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{\color{blue}{4 \cdot \left(a \cdot c\right)}}}}{2 \cdot a} \]
    2. lower-*.f6499.3

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{4 \cdot \color{blue}{\left(a \cdot c\right)}}}}{2 \cdot a} \]
  10. Applied rewrites99.3%

    \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{\color{blue}{4 \cdot \left(a \cdot c\right)}}}}{2 \cdot a} \]
  11. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{4 \cdot \left(a \cdot c\right)}}}}{2 \cdot a} \]
    2. lift-/.f64N/A

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

      \[\leadsto \frac{\color{blue}{\frac{4 \cdot \left(a \cdot c\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}}}{2 \cdot a} \]
    4. lower-/.f6499.4

      \[\leadsto \frac{\color{blue}{\frac{4 \cdot \left(a \cdot c\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}}}{2 \cdot a} \]
  12. Applied rewrites99.4%

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

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

Alternative 5: 99.2% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \frac{c \cdot \left(a \cdot 4\right)}{b + \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}} \cdot \frac{0.5}{-a} \end{array} \]
(FPCore (a b c)
 :precision binary64
 (*
  (/ (* c (* a 4.0)) (+ b (sqrt (* (fma -4.0 c (* (/ b a) b)) a))))
  (/ 0.5 (- a))))
double code(double a, double b, double c) {
	return ((c * (a * 4.0)) / (b + sqrt((fma(-4.0, c, ((b / a) * b)) * a)))) * (0.5 / -a);
}
function code(a, b, c)
	return Float64(Float64(Float64(c * Float64(a * 4.0)) / Float64(b + sqrt(Float64(fma(-4.0, c, Float64(Float64(b / a) * b)) * a)))) * Float64(0.5 / Float64(-a)))
end
code[a_, b_, c_] := N[(N[(N[(c * N[(a * 4.0), $MachinePrecision]), $MachinePrecision] / N[(b + N[Sqrt[N[(N[(-4.0 * c + N[(N[(b / a), $MachinePrecision] * b), $MachinePrecision]), $MachinePrecision] * a), $MachinePrecision]], $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * N[(0.5 / (-a)), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{c \cdot \left(a \cdot 4\right)}{b + \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}} \cdot \frac{0.5}{-a}
\end{array}
Derivation
  1. Initial program 32.4%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in a around inf

    \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{a \cdot \left(\frac{{b}^{2}}{a} - 4 \cdot c\right)}}}{2 \cdot a} \]
  4. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(\frac{{b}^{2}}{a} - 4 \cdot c\right) \cdot a}}}{2 \cdot a} \]
    2. lower-*.f64N/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(\frac{{b}^{2}}{a} - 4 \cdot c\right) \cdot a}}}{2 \cdot a} \]
    3. cancel-sign-sub-invN/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(\frac{{b}^{2}}{a} + \left(\mathsf{neg}\left(4\right)\right) \cdot c\right)} \cdot a}}{2 \cdot a} \]
    4. metadata-evalN/A

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

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\left(-4 \cdot c + \frac{{b}^{2}}{a}\right)} \cdot a}}{2 \cdot a} \]
    6. lower-fma.f64N/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(-4, c, \frac{{b}^{2}}{a}\right)} \cdot a}}{2 \cdot a} \]
    7. unpow2N/A

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

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, \color{blue}{b \cdot \frac{b}{a}}\right) \cdot a}}{2 \cdot a} \]
    9. lower-*.f64N/A

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, \color{blue}{b \cdot \frac{b}{a}}\right) \cdot a}}{2 \cdot a} \]
    10. lower-/.f6432.3

      \[\leadsto \frac{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, b \cdot \color{blue}{\frac{b}{a}}\right) \cdot a}}{2 \cdot a} \]
  5. Applied rewrites32.3%

    \[\leadsto \frac{\left(-b\right) + \sqrt{\color{blue}{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}{2 \cdot a} \]
  6. Step-by-step derivation
    1. lift-+.f64N/A

      \[\leadsto \frac{\color{blue}{\left(-b\right) + \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}{2 \cdot a} \]
    2. flip-+N/A

      \[\leadsto \frac{\color{blue}{\frac{\left(-b\right) \cdot \left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a} \cdot \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}}{2 \cdot a} \]
    3. clear-numN/A

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}{\left(-b\right) \cdot \left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a} \cdot \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}}}{2 \cdot a} \]
    4. lower-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}{\left(-b\right) \cdot \left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a} \cdot \sqrt{\mathsf{fma}\left(-4, c, b \cdot \frac{b}{a}\right) \cdot a}}}}}{2 \cdot a} \]
  7. Applied rewrites32.9%

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

    \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{\color{blue}{4 \cdot \left(a \cdot c\right)}}}}{2 \cdot a} \]
  9. Step-by-step derivation
    1. lower-*.f64N/A

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{\color{blue}{4 \cdot \left(a \cdot c\right)}}}}{2 \cdot a} \]
    2. lower-*.f6499.3

      \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{4 \cdot \color{blue}{\left(a \cdot c\right)}}}}{2 \cdot a} \]
  10. Applied rewrites99.3%

    \[\leadsto \frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{\color{blue}{4 \cdot \left(a \cdot c\right)}}}}{2 \cdot a} \]
  11. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{4 \cdot \left(a \cdot c\right)}}}{2 \cdot a}} \]
    2. div-invN/A

      \[\leadsto \color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{4 \cdot \left(a \cdot c\right)}} \cdot \frac{1}{2 \cdot a}} \]
    3. lower-*.f64N/A

      \[\leadsto \color{blue}{\frac{1}{\frac{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}}{4 \cdot \left(a \cdot c\right)}} \cdot \frac{1}{2 \cdot a}} \]
  12. Applied rewrites99.3%

    \[\leadsto \color{blue}{\frac{c \cdot \left(a \cdot 4\right)}{\left(-b\right) - \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}} \cdot \frac{0.5}{a}} \]
  13. Final simplification99.3%

    \[\leadsto \frac{c \cdot \left(a \cdot 4\right)}{b + \sqrt{\mathsf{fma}\left(-4, c, \frac{b}{a} \cdot b\right) \cdot a}} \cdot \frac{0.5}{-a} \]
  14. Add Preprocessing

Alternative 6: 90.8% accurate, 1.2× speedup?

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

\\
\frac{\left(-c\right) - \frac{a \cdot \left(c \cdot c\right)}{b \cdot b}}{b}
\end{array}
Derivation
  1. Initial program 32.4%

    \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
  2. Add Preprocessing
  3. Taylor expanded in a around 0

    \[\leadsto \color{blue}{-1 \cdot \frac{c}{b} + a \cdot \left(-1 \cdot \frac{{c}^{2}}{{b}^{3}} + a \cdot \left(-2 \cdot \frac{{c}^{3}}{{b}^{5}} + \frac{-1}{4} \cdot \frac{a \cdot \left(4 \cdot \frac{{c}^{4}}{{b}^{6}} + 16 \cdot \frac{{c}^{4}}{{b}^{6}}\right)}{b}\right)\right)} \]
  4. Applied rewrites94.9%

    \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.25 \cdot a, \frac{{c}^{4}}{{b}^{6}} \cdot \frac{20}{b}, \frac{{c}^{3} \cdot -2}{{b}^{5}}\right), a, \left(-c\right) \cdot \frac{c}{{b}^{3}}\right), a, \frac{-c}{b}\right)} \]
  5. Taylor expanded in b around 0

    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\frac{-5 \cdot \left(a \cdot {c}^{4}\right) + -2 \cdot \left({b}^{2} \cdot {c}^{3}\right)}{{b}^{7}}, a, \left(-c\right) \cdot \frac{c}{{b}^{3}}\right), a, \frac{-c}{b}\right) \]
  6. Step-by-step derivation
    1. Applied rewrites94.9%

      \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\frac{\mathsf{fma}\left(-5 \cdot a, {c}^{4}, \left(-2 \cdot \left(b \cdot b\right)\right) \cdot {c}^{3}\right)}{{b}^{7}}, a, \left(-c\right) \cdot \frac{c}{{b}^{3}}\right), a, \frac{-c}{b}\right) \]
    2. Taylor expanded in b around -inf

      \[\leadsto -1 \cdot \color{blue}{\frac{c + \frac{a \cdot {c}^{2}}{{b}^{2}}}{b}} \]
    3. Step-by-step derivation
      1. Applied rewrites89.6%

        \[\leadsto -\frac{c + \frac{a \cdot \left(c \cdot c\right)}{b \cdot b}}{b} \]
      2. Final simplification89.6%

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

      Alternative 7: 90.5% accurate, 1.2× speedup?

      \[\begin{array}{l} \\ \frac{-1 - \frac{c \cdot a}{b \cdot b}}{b} \cdot c \end{array} \]
      (FPCore (a b c) :precision binary64 (* (/ (- -1.0 (/ (* c a) (* b b))) b) c))
      double code(double a, double b, double c) {
      	return ((-1.0 - ((c * a) / (b * b))) / b) * c;
      }
      
      real(8) function code(a, b, c)
          real(8), intent (in) :: a
          real(8), intent (in) :: b
          real(8), intent (in) :: c
          code = (((-1.0d0) - ((c * a) / (b * b))) / b) * c
      end function
      
      public static double code(double a, double b, double c) {
      	return ((-1.0 - ((c * a) / (b * b))) / b) * c;
      }
      
      def code(a, b, c):
      	return ((-1.0 - ((c * a) / (b * b))) / b) * c
      
      function code(a, b, c)
      	return Float64(Float64(Float64(-1.0 - Float64(Float64(c * a) / Float64(b * b))) / b) * c)
      end
      
      function tmp = code(a, b, c)
      	tmp = ((-1.0 - ((c * a) / (b * b))) / b) * c;
      end
      
      code[a_, b_, c_] := N[(N[(N[(-1.0 - N[(N[(c * a), $MachinePrecision] / N[(b * b), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / b), $MachinePrecision] * c), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \frac{-1 - \frac{c \cdot a}{b \cdot b}}{b} \cdot c
      \end{array}
      
      Derivation
      1. Initial program 32.4%

        \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
      2. Add Preprocessing
      3. Taylor expanded in c around 0

        \[\leadsto \color{blue}{c \cdot \left(-1 \cdot \frac{a \cdot c}{{b}^{3}} - \frac{1}{b}\right)} \]
      4. Step-by-step derivation
        1. *-commutativeN/A

          \[\leadsto \color{blue}{\left(-1 \cdot \frac{a \cdot c}{{b}^{3}} - \frac{1}{b}\right) \cdot c} \]
        2. sub-negN/A

          \[\leadsto \color{blue}{\left(-1 \cdot \frac{a \cdot c}{{b}^{3}} + \left(\mathsf{neg}\left(\frac{1}{b}\right)\right)\right)} \cdot c \]
        3. distribute-neg-fracN/A

          \[\leadsto \left(-1 \cdot \frac{a \cdot c}{{b}^{3}} + \color{blue}{\frac{\mathsf{neg}\left(1\right)}{b}}\right) \cdot c \]
        4. metadata-evalN/A

          \[\leadsto \left(-1 \cdot \frac{a \cdot c}{{b}^{3}} + \frac{\color{blue}{-1}}{b}\right) \cdot c \]
        5. associate-*r/N/A

          \[\leadsto \left(\color{blue}{\frac{-1 \cdot \left(a \cdot c\right)}{{b}^{3}}} + \frac{-1}{b}\right) \cdot c \]
        6. associate-*r*N/A

          \[\leadsto \left(\frac{\color{blue}{\left(-1 \cdot a\right) \cdot c}}{{b}^{3}} + \frac{-1}{b}\right) \cdot c \]
        7. associate-*l/N/A

          \[\leadsto \left(\color{blue}{\frac{-1 \cdot a}{{b}^{3}} \cdot c} + \frac{-1}{b}\right) \cdot c \]
        8. associate-*r/N/A

          \[\leadsto \left(\color{blue}{\left(-1 \cdot \frac{a}{{b}^{3}}\right)} \cdot c + \frac{-1}{b}\right) \cdot c \]
        9. lower-*.f64N/A

          \[\leadsto \color{blue}{\left(\left(-1 \cdot \frac{a}{{b}^{3}}\right) \cdot c + \frac{-1}{b}\right) \cdot c} \]
      5. Applied rewrites89.5%

        \[\leadsto \color{blue}{\left(-\mathsf{fma}\left(\frac{c}{{b}^{3}}, a, \frac{1}{b}\right)\right) \cdot c} \]
      6. Step-by-step derivation
        1. Applied rewrites89.5%

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

        Alternative 8: 81.2% accurate, 3.6× 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 32.4%

          \[\frac{\left(-b\right) + \sqrt{b \cdot b - \left(4 \cdot a\right) \cdot c}}{2 \cdot a} \]
        2. Add Preprocessing
        3. Taylor expanded in a around 0

          \[\leadsto \color{blue}{-1 \cdot \frac{c}{b}} \]
        4. Step-by-step derivation
          1. associate-*r/N/A

            \[\leadsto \color{blue}{\frac{-1 \cdot c}{b}} \]
          2. lower-/.f64N/A

            \[\leadsto \color{blue}{\frac{-1 \cdot c}{b}} \]
          3. mul-1-negN/A

            \[\leadsto \frac{\color{blue}{\mathsf{neg}\left(c\right)}}{b} \]
          4. lower-neg.f6480.5

            \[\leadsto \frac{\color{blue}{-c}}{b} \]
        5. Applied rewrites80.5%

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

        Reproduce

        ?
        herbie shell --seed 2024308 
        (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)))