
(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(4.0 * Float64(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[(4.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(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(4.0 * Float64(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[(4.0 * N[(a * c), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(2.0 * a), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
\\
\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(a \cdot c\right)}}{2 \cdot a}
\end{array}
(FPCore (a b c)
:precision binary64
(if (<= b -9.8e-54)
(/ c (- b))
(if (<= b 2.7e+89)
(/ (- (- b) (sqrt (- (* b b) (* 4.0 (* c a))))) (* a 2.0))
(- (/ c b) (/ b a)))))
double code(double a, double b, double c) {
double tmp;
if (b <= -9.8e-54) {
tmp = c / -b;
} else if (b <= 2.7e+89) {
tmp = (-b - sqrt(((b * b) - (4.0 * (c * a))))) / (a * 2.0);
} else {
tmp = (c / b) - (b / a);
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= (-9.8d-54)) then
tmp = c / -b
else if (b <= 2.7d+89) then
tmp = (-b - sqrt(((b * b) - (4.0d0 * (c * a))))) / (a * 2.0d0)
else
tmp = (c / b) - (b / a)
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -9.8e-54) {
tmp = c / -b;
} else if (b <= 2.7e+89) {
tmp = (-b - Math.sqrt(((b * b) - (4.0 * (c * a))))) / (a * 2.0);
} else {
tmp = (c / b) - (b / a);
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -9.8e-54: tmp = c / -b elif b <= 2.7e+89: tmp = (-b - math.sqrt(((b * b) - (4.0 * (c * a))))) / (a * 2.0) else: tmp = (c / b) - (b / a) return tmp
function code(a, b, c) tmp = 0.0 if (b <= -9.8e-54) tmp = Float64(c / Float64(-b)); elseif (b <= 2.7e+89) tmp = Float64(Float64(Float64(-b) - sqrt(Float64(Float64(b * b) - Float64(4.0 * Float64(c * a))))) / Float64(a * 2.0)); else tmp = Float64(Float64(c / b) - Float64(b / a)); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -9.8e-54) tmp = c / -b; elseif (b <= 2.7e+89) tmp = (-b - sqrt(((b * b) - (4.0 * (c * a))))) / (a * 2.0); else tmp = (c / b) - (b / a); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -9.8e-54], N[(c / (-b)), $MachinePrecision], If[LessEqual[b, 2.7e+89], N[(N[((-b) - N[Sqrt[N[(N[(b * b), $MachinePrecision] - N[(4.0 * N[(c * a), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -9.8 \cdot 10^{-54}:\\
\;\;\;\;\frac{c}{-b}\\
\mathbf{elif}\;b \leq 2.7 \cdot 10^{+89}:\\
\;\;\;\;\frac{\left(-b\right) - \sqrt{b \cdot b - 4 \cdot \left(c \cdot a\right)}}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\end{array}
\end{array}
if b < -9.80000000000000042e-54Initial program 15.6%
div-sub14.1%
sub-neg14.1%
neg-mul-114.1%
*-commutative14.1%
associate-/l*14.1%
distribute-neg-frac14.1%
neg-mul-114.1%
*-commutative14.1%
associate-/l*14.1%
distribute-rgt-out15.5%
associate-/r*15.5%
metadata-eval15.5%
sub-neg15.5%
+-commutative15.5%
Simplified15.5%
Taylor expanded in b around -inf 80.9%
mul-1-neg80.9%
distribute-neg-frac280.9%
Simplified80.9%
if -9.80000000000000042e-54 < b < 2.7e89Initial program 76.7%
if 2.7e89 < b Initial program 48.4%
div-sub48.4%
sub-neg48.4%
neg-mul-148.4%
*-commutative48.4%
associate-/l*48.4%
distribute-neg-frac48.4%
neg-mul-148.4%
*-commutative48.4%
associate-/l*48.4%
distribute-rgt-out48.4%
associate-/r*48.4%
metadata-eval48.4%
sub-neg48.4%
+-commutative48.4%
Simplified48.5%
Taylor expanded in c around 0 92.5%
+-commutative92.5%
mul-1-neg92.5%
unsub-neg92.5%
Simplified92.5%
Final simplification81.3%
(FPCore (a b c)
:precision binary64
(if (<= b -3.15e-52)
(/ c (- b))
(if (<= b 7.8e-88)
(/ (- (- b) (sqrt (* c (* a -4.0)))) (* a 2.0))
(- (/ c b) (/ b a)))))
double code(double a, double b, double c) {
double tmp;
if (b <= -3.15e-52) {
tmp = c / -b;
} else if (b <= 7.8e-88) {
tmp = (-b - sqrt((c * (a * -4.0)))) / (a * 2.0);
} else {
tmp = (c / b) - (b / a);
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= (-3.15d-52)) then
tmp = c / -b
else if (b <= 7.8d-88) then
tmp = (-b - sqrt((c * (a * (-4.0d0))))) / (a * 2.0d0)
else
tmp = (c / b) - (b / a)
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -3.15e-52) {
tmp = c / -b;
} else if (b <= 7.8e-88) {
tmp = (-b - Math.sqrt((c * (a * -4.0)))) / (a * 2.0);
} else {
tmp = (c / b) - (b / a);
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -3.15e-52: tmp = c / -b elif b <= 7.8e-88: tmp = (-b - math.sqrt((c * (a * -4.0)))) / (a * 2.0) else: tmp = (c / b) - (b / a) return tmp
function code(a, b, c) tmp = 0.0 if (b <= -3.15e-52) tmp = Float64(c / Float64(-b)); elseif (b <= 7.8e-88) tmp = Float64(Float64(Float64(-b) - sqrt(Float64(c * Float64(a * -4.0)))) / Float64(a * 2.0)); else tmp = Float64(Float64(c / b) - Float64(b / a)); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -3.15e-52) tmp = c / -b; elseif (b <= 7.8e-88) tmp = (-b - sqrt((c * (a * -4.0)))) / (a * 2.0); else tmp = (c / b) - (b / a); end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -3.15e-52], N[(c / (-b)), $MachinePrecision], If[LessEqual[b, 7.8e-88], N[(N[((-b) - N[Sqrt[N[(c * N[(a * -4.0), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]), $MachinePrecision] / N[(a * 2.0), $MachinePrecision]), $MachinePrecision], N[(N[(c / b), $MachinePrecision] - N[(b / a), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -3.15 \cdot 10^{-52}:\\
\;\;\;\;\frac{c}{-b}\\
\mathbf{elif}\;b \leq 7.8 \cdot 10^{-88}:\\
\;\;\;\;\frac{\left(-b\right) - \sqrt{c \cdot \left(a \cdot -4\right)}}{a \cdot 2}\\
\mathbf{else}:\\
\;\;\;\;\frac{c}{b} - \frac{b}{a}\\
\end{array}
\end{array}
if b < -3.1500000000000002e-52Initial program 15.6%
div-sub14.1%
sub-neg14.1%
neg-mul-114.1%
*-commutative14.1%
associate-/l*14.1%
distribute-neg-frac14.1%
neg-mul-114.1%
*-commutative14.1%
associate-/l*14.1%
distribute-rgt-out15.5%
associate-/r*15.5%
metadata-eval15.5%
sub-neg15.5%
+-commutative15.5%
Simplified15.5%
Taylor expanded in b around -inf 80.9%
mul-1-neg80.9%
distribute-neg-frac280.9%
Simplified80.9%
if -3.1500000000000002e-52 < b < 7.79999999999999985e-88Initial program 72.7%
*-commutative72.7%
*-commutative72.7%
sqr-neg72.7%
*-commutative72.7%
sqr-neg72.7%
*-commutative72.7%
associate-*r*72.7%
Simplified72.7%
Taylor expanded in b around 0 69.3%
associate-*r*69.3%
*-commutative69.3%
Simplified69.3%
if 7.79999999999999985e-88 < b Initial program 63.8%
div-sub63.8%
sub-neg63.8%
neg-mul-163.8%
*-commutative63.8%
associate-/l*63.8%
distribute-neg-frac63.8%
neg-mul-163.8%
*-commutative63.8%
associate-/l*63.7%
distribute-rgt-out63.7%
associate-/r*63.7%
metadata-eval63.7%
sub-neg63.7%
+-commutative63.7%
Simplified63.8%
Taylor expanded in c around 0 82.1%
+-commutative82.1%
mul-1-neg82.1%
unsub-neg82.1%
Simplified82.1%
Final simplification77.9%
(FPCore (a b c) :precision binary64 (if (<= b -2e-310) (/ c (- b)) (/ (- b) a)))
double code(double a, double b, double c) {
double tmp;
if (b <= -2e-310) {
tmp = c / -b;
} else {
tmp = -b / a;
}
return tmp;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
real(8) :: tmp
if (b <= (-2d-310)) then
tmp = c / -b
else
tmp = -b / a
end if
code = tmp
end function
public static double code(double a, double b, double c) {
double tmp;
if (b <= -2e-310) {
tmp = c / -b;
} else {
tmp = -b / a;
}
return tmp;
}
def code(a, b, c): tmp = 0 if b <= -2e-310: tmp = c / -b else: tmp = -b / a return tmp
function code(a, b, c) tmp = 0.0 if (b <= -2e-310) tmp = Float64(c / Float64(-b)); else tmp = Float64(Float64(-b) / a); end return tmp end
function tmp_2 = code(a, b, c) tmp = 0.0; if (b <= -2e-310) tmp = c / -b; else tmp = -b / a; end tmp_2 = tmp; end
code[a_, b_, c_] := If[LessEqual[b, -2e-310], N[(c / (-b)), $MachinePrecision], N[((-b) / a), $MachinePrecision]]
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;b \leq -2 \cdot 10^{-310}:\\
\;\;\;\;\frac{c}{-b}\\
\mathbf{else}:\\
\;\;\;\;\frac{-b}{a}\\
\end{array}
\end{array}
if b < -1.999999999999994e-310Initial program 31.7%
div-sub30.8%
sub-neg30.8%
neg-mul-130.8%
*-commutative30.8%
associate-/l*30.7%
distribute-neg-frac30.7%
neg-mul-130.7%
*-commutative30.7%
associate-/l*30.7%
distribute-rgt-out31.6%
associate-/r*31.6%
metadata-eval31.6%
sub-neg31.6%
+-commutative31.6%
Simplified31.6%
Taylor expanded in b around -inf 63.8%
mul-1-neg63.8%
distribute-neg-frac263.8%
Simplified63.8%
if -1.999999999999994e-310 < b Initial program 69.4%
div-sub69.4%
sub-neg69.4%
neg-mul-169.4%
*-commutative69.4%
associate-/l*69.4%
distribute-neg-frac69.4%
neg-mul-169.4%
*-commutative69.4%
associate-/l*69.3%
distribute-rgt-out69.3%
associate-/r*69.3%
metadata-eval69.3%
sub-neg69.3%
+-commutative69.3%
Simplified69.3%
Taylor expanded in a around 0 66.4%
associate-*r/66.4%
mul-1-neg66.4%
Simplified66.4%
(FPCore (a b c) :precision binary64 (/ c (- b)))
double code(double a, double b, double c) {
return c / -b;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = c / -b
end function
public static double code(double a, double b, double c) {
return c / -b;
}
def code(a, b, c): return c / -b
function code(a, b, c) return Float64(c / Float64(-b)) end
function tmp = code(a, b, c) tmp = c / -b; end
code[a_, b_, c_] := N[(c / (-b)), $MachinePrecision]
\begin{array}{l}
\\
\frac{c}{-b}
\end{array}
Initial program 47.8%
div-sub47.2%
sub-neg47.2%
neg-mul-147.2%
*-commutative47.2%
associate-/l*47.2%
distribute-neg-frac47.2%
neg-mul-147.2%
*-commutative47.2%
associate-/l*47.1%
distribute-rgt-out47.7%
associate-/r*47.7%
metadata-eval47.7%
sub-neg47.7%
+-commutative47.7%
Simplified47.7%
Taylor expanded in b around -inf 37.6%
mul-1-neg37.6%
distribute-neg-frac237.6%
Simplified37.6%
(FPCore (a b c) :precision binary64 -0.125)
double code(double a, double b, double c) {
return -0.125;
}
real(8) function code(a, b, c)
real(8), intent (in) :: a
real(8), intent (in) :: b
real(8), intent (in) :: c
code = -0.125d0
end function
public static double code(double a, double b, double c) {
return -0.125;
}
def code(a, b, c): return -0.125
function code(a, b, c) return -0.125 end
function tmp = code(a, b, c) tmp = -0.125; end
code[a_, b_, c_] := -0.125
\begin{array}{l}
\\
-0.125
\end{array}
Initial program 47.8%
div-sub47.2%
sub-neg47.2%
neg-mul-147.2%
*-commutative47.2%
associate-/l*47.2%
distribute-neg-frac47.2%
neg-mul-147.2%
*-commutative47.2%
associate-/l*47.1%
distribute-rgt-out47.7%
associate-/r*47.7%
metadata-eval47.7%
sub-neg47.7%
+-commutative47.7%
Simplified47.7%
associate-*l/47.8%
clear-num47.6%
*-commutative47.6%
pow247.6%
Applied egg-rr47.6%
clear-num47.7%
associate-/r/47.6%
*-commutative47.6%
associate-/r*47.6%
metadata-eval47.6%
Applied egg-rr47.6%
Taylor expanded in b around inf 29.8%
Simplified3.4%
Final simplification3.4%
(FPCore (a b c)
:precision binary64
(let* ((t_0 (fabs (/ b 2.0)))
(t_1 (* (sqrt (fabs a)) (sqrt (fabs c))))
(t_2
(if (== (copysign a c) a)
(* (sqrt (- t_0 t_1)) (sqrt (+ t_0 t_1)))
(hypot (/ b 2.0) t_1))))
(if (< b 0.0) (/ c (- t_2 (/ b 2.0))) (/ (+ (/ b 2.0) t_2) (- a)))))
double code(double a, double b, double c) {
double t_0 = fabs((b / 2.0));
double t_1 = sqrt(fabs(a)) * sqrt(fabs(c));
double tmp;
if (copysign(a, c) == a) {
tmp = sqrt((t_0 - t_1)) * sqrt((t_0 + t_1));
} else {
tmp = hypot((b / 2.0), t_1);
}
double t_2 = tmp;
double tmp_1;
if (b < 0.0) {
tmp_1 = c / (t_2 - (b / 2.0));
} else {
tmp_1 = ((b / 2.0) + t_2) / -a;
}
return tmp_1;
}
public static double code(double a, double b, double c) {
double t_0 = Math.abs((b / 2.0));
double t_1 = Math.sqrt(Math.abs(a)) * Math.sqrt(Math.abs(c));
double tmp;
if (Math.copySign(a, c) == a) {
tmp = Math.sqrt((t_0 - t_1)) * Math.sqrt((t_0 + t_1));
} else {
tmp = Math.hypot((b / 2.0), t_1);
}
double t_2 = tmp;
double tmp_1;
if (b < 0.0) {
tmp_1 = c / (t_2 - (b / 2.0));
} else {
tmp_1 = ((b / 2.0) + t_2) / -a;
}
return tmp_1;
}
def code(a, b, c): t_0 = math.fabs((b / 2.0)) t_1 = math.sqrt(math.fabs(a)) * math.sqrt(math.fabs(c)) tmp = 0 if math.copysign(a, c) == a: tmp = math.sqrt((t_0 - t_1)) * math.sqrt((t_0 + t_1)) else: tmp = math.hypot((b / 2.0), t_1) t_2 = tmp tmp_1 = 0 if b < 0.0: tmp_1 = c / (t_2 - (b / 2.0)) else: tmp_1 = ((b / 2.0) + t_2) / -a return tmp_1
function code(a, b, c) t_0 = abs(Float64(b / 2.0)) t_1 = Float64(sqrt(abs(a)) * sqrt(abs(c))) tmp = 0.0 if (copysign(a, c) == a) tmp = Float64(sqrt(Float64(t_0 - t_1)) * sqrt(Float64(t_0 + t_1))); else tmp = hypot(Float64(b / 2.0), t_1); end t_2 = tmp tmp_1 = 0.0 if (b < 0.0) tmp_1 = Float64(c / Float64(t_2 - Float64(b / 2.0))); else tmp_1 = Float64(Float64(Float64(b / 2.0) + t_2) / Float64(-a)); end return tmp_1 end
function tmp_3 = code(a, b, c) t_0 = abs((b / 2.0)); t_1 = sqrt(abs(a)) * sqrt(abs(c)); tmp = 0.0; if ((sign(c) * abs(a)) == a) tmp = sqrt((t_0 - t_1)) * sqrt((t_0 + t_1)); else tmp = hypot((b / 2.0), t_1); end t_2 = tmp; tmp_2 = 0.0; if (b < 0.0) tmp_2 = c / (t_2 - (b / 2.0)); else tmp_2 = ((b / 2.0) + t_2) / -a; end tmp_3 = tmp_2; end
code[a_, b_, c_] := Block[{t$95$0 = N[Abs[N[(b / 2.0), $MachinePrecision]], $MachinePrecision]}, Block[{t$95$1 = N[(N[Sqrt[N[Abs[a], $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[Abs[c], $MachinePrecision]], $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = If[Equal[N[With[{TMP1 = Abs[a], TMP2 = Sign[c]}, TMP1 * If[TMP2 == 0, 1, TMP2]], $MachinePrecision], a], N[(N[Sqrt[N[(t$95$0 - t$95$1), $MachinePrecision]], $MachinePrecision] * N[Sqrt[N[(t$95$0 + t$95$1), $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[Sqrt[N[(b / 2.0), $MachinePrecision] ^ 2 + t$95$1 ^ 2], $MachinePrecision]]}, If[Less[b, 0.0], N[(c / N[(t$95$2 - N[(b / 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(b / 2.0), $MachinePrecision] + t$95$2), $MachinePrecision] / (-a)), $MachinePrecision]]]]]
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left|\frac{b}{2}\right|\\
t_1 := \sqrt{\left|a\right|} \cdot \sqrt{\left|c\right|}\\
t_2 := \begin{array}{l}
\mathbf{if}\;\mathsf{copysign}\left(a, c\right) = a:\\
\;\;\;\;\sqrt{t\_0 - t\_1} \cdot \sqrt{t\_0 + t\_1}\\
\mathbf{else}:\\
\;\;\;\;\mathsf{hypot}\left(\frac{b}{2}, t\_1\right)\\
\end{array}\\
\mathbf{if}\;b < 0:\\
\;\;\;\;\frac{c}{t\_2 - \frac{b}{2}}\\
\mathbf{else}:\\
\;\;\;\;\frac{\frac{b}{2} + t\_2}{-a}\\
\end{array}
\end{array}
herbie shell --seed 2024105
(FPCore (a b c)
:name "quadm (p42, negative)"
:precision binary64
:herbie-expected 10
:alt
(if (< b 0.0) (/ c (- (if (== (copysign a c) a) (* (sqrt (- (fabs (/ b 2.0)) (* (sqrt (fabs a)) (sqrt (fabs c))))) (sqrt (+ (fabs (/ b 2.0)) (* (sqrt (fabs a)) (sqrt (fabs c)))))) (hypot (/ b 2.0) (* (sqrt (fabs a)) (sqrt (fabs c))))) (/ b 2.0))) (/ (+ (/ b 2.0) (if (== (copysign a c) a) (* (sqrt (- (fabs (/ b 2.0)) (* (sqrt (fabs a)) (sqrt (fabs c))))) (sqrt (+ (fabs (/ b 2.0)) (* (sqrt (fabs a)) (sqrt (fabs c)))))) (hypot (/ b 2.0) (* (sqrt (fabs a)) (sqrt (fabs c)))))) (- a)))
(/ (- (- b) (sqrt (- (* b b) (* 4.0 (* a c))))) (* 2.0 a)))