Average Error: 34.0 → 6.8
Time: 20.2s
Precision: 64
\[\frac{\left(-b_2\right) - \sqrt{b_2 \cdot b_2 - a \cdot c}}{a}\]
\[\begin{array}{l} \mathbf{if}\;b_2 \le -3.727723973148742563324153150500151191249 \cdot 10^{105}:\\ \;\;\;\;\frac{-1}{2} \cdot \frac{c}{b_2}\\ \mathbf{elif}\;b_2 \le 1.364529283357116165462040672443911208369 \cdot 10^{-246}:\\ \;\;\;\;\frac{c}{\sqrt{b_2 \cdot b_2 - a \cdot c} - b_2}\\ \mathbf{elif}\;b_2 \le 4.198650993474429809884798868723112488797 \cdot 10^{74}:\\ \;\;\;\;\frac{-b_2}{a} - \frac{\sqrt{b_2 \cdot b_2 - a \cdot c}}{a}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2} \cdot \frac{c}{b_2} - 2 \cdot \frac{b_2}{a}\\ \end{array}\]
\frac{\left(-b_2\right) - \sqrt{b_2 \cdot b_2 - a \cdot c}}{a}
\begin{array}{l}
\mathbf{if}\;b_2 \le -3.727723973148742563324153150500151191249 \cdot 10^{105}:\\
\;\;\;\;\frac{-1}{2} \cdot \frac{c}{b_2}\\

\mathbf{elif}\;b_2 \le 1.364529283357116165462040672443911208369 \cdot 10^{-246}:\\
\;\;\;\;\frac{c}{\sqrt{b_2 \cdot b_2 - a \cdot c} - b_2}\\

\mathbf{elif}\;b_2 \le 4.198650993474429809884798868723112488797 \cdot 10^{74}:\\
\;\;\;\;\frac{-b_2}{a} - \frac{\sqrt{b_2 \cdot b_2 - a \cdot c}}{a}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{2} \cdot \frac{c}{b_2} - 2 \cdot \frac{b_2}{a}\\

\end{array}
double f(double a, double b_2, double c) {
        double r63958 = b_2;
        double r63959 = -r63958;
        double r63960 = r63958 * r63958;
        double r63961 = a;
        double r63962 = c;
        double r63963 = r63961 * r63962;
        double r63964 = r63960 - r63963;
        double r63965 = sqrt(r63964);
        double r63966 = r63959 - r63965;
        double r63967 = r63966 / r63961;
        return r63967;
}

double f(double a, double b_2, double c) {
        double r63968 = b_2;
        double r63969 = -3.7277239731487426e+105;
        bool r63970 = r63968 <= r63969;
        double r63971 = -0.5;
        double r63972 = c;
        double r63973 = r63972 / r63968;
        double r63974 = r63971 * r63973;
        double r63975 = 1.3645292833571162e-246;
        bool r63976 = r63968 <= r63975;
        double r63977 = r63968 * r63968;
        double r63978 = a;
        double r63979 = r63978 * r63972;
        double r63980 = r63977 - r63979;
        double r63981 = sqrt(r63980);
        double r63982 = r63981 - r63968;
        double r63983 = r63972 / r63982;
        double r63984 = 4.19865099347443e+74;
        bool r63985 = r63968 <= r63984;
        double r63986 = -r63968;
        double r63987 = r63986 / r63978;
        double r63988 = r63981 / r63978;
        double r63989 = r63987 - r63988;
        double r63990 = 0.5;
        double r63991 = r63990 * r63973;
        double r63992 = 2.0;
        double r63993 = r63968 / r63978;
        double r63994 = r63992 * r63993;
        double r63995 = r63991 - r63994;
        double r63996 = r63985 ? r63989 : r63995;
        double r63997 = r63976 ? r63983 : r63996;
        double r63998 = r63970 ? r63974 : r63997;
        return r63998;
}

Error

Bits error versus a

Bits error versus b_2

Bits error versus c

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Derivation

  1. Split input into 4 regimes
  2. if b_2 < -3.7277239731487426e+105

    1. Initial program 59.9

      \[\frac{\left(-b_2\right) - \sqrt{b_2 \cdot b_2 - a \cdot c}}{a}\]
    2. Taylor expanded around -inf 2.4

      \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{c}{b_2}}\]

    if -3.7277239731487426e+105 < b_2 < 1.3645292833571162e-246

    1. Initial program 30.7

      \[\frac{\left(-b_2\right) - \sqrt{b_2 \cdot b_2 - a \cdot c}}{a}\]
    2. Using strategy rm
    3. Applied flip--30.8

      \[\leadsto \frac{\color{blue}{\frac{\left(-b_2\right) \cdot \left(-b_2\right) - \sqrt{b_2 \cdot b_2 - a \cdot c} \cdot \sqrt{b_2 \cdot b_2 - a \cdot c}}{\left(-b_2\right) + \sqrt{b_2 \cdot b_2 - a \cdot c}}}}{a}\]
    4. Simplified15.7

      \[\leadsto \frac{\frac{\color{blue}{a \cdot c}}{\left(-b_2\right) + \sqrt{b_2 \cdot b_2 - a \cdot c}}}{a}\]
    5. Simplified15.7

      \[\leadsto \frac{\frac{a \cdot c}{\color{blue}{\sqrt{b_2 \cdot b_2 - a \cdot c} - b_2}}}{a}\]
    6. Using strategy rm
    7. Applied *-un-lft-identity15.7

      \[\leadsto \frac{\frac{a \cdot c}{\sqrt{b_2 \cdot b_2 - a \cdot c} - b_2}}{\color{blue}{1 \cdot a}}\]
    8. Applied *-un-lft-identity15.7

      \[\leadsto \frac{\color{blue}{1 \cdot \frac{a \cdot c}{\sqrt{b_2 \cdot b_2 - a \cdot c} - b_2}}}{1 \cdot a}\]
    9. Applied times-frac15.7

      \[\leadsto \color{blue}{\frac{1}{1} \cdot \frac{\frac{a \cdot c}{\sqrt{b_2 \cdot b_2 - a \cdot c} - b_2}}{a}}\]
    10. Simplified15.7

      \[\leadsto \color{blue}{1} \cdot \frac{\frac{a \cdot c}{\sqrt{b_2 \cdot b_2 - a \cdot c} - b_2}}{a}\]
    11. Simplified8.5

      \[\leadsto 1 \cdot \color{blue}{\left(\frac{c}{\sqrt{b_2 \cdot b_2 - a \cdot c} - b_2} \cdot 1\right)}\]

    if 1.3645292833571162e-246 < b_2 < 4.19865099347443e+74

    1. Initial program 9.3

      \[\frac{\left(-b_2\right) - \sqrt{b_2 \cdot b_2 - a \cdot c}}{a}\]
    2. Using strategy rm
    3. Applied div-sub9.3

      \[\leadsto \color{blue}{\frac{-b_2}{a} - \frac{\sqrt{b_2 \cdot b_2 - a \cdot c}}{a}}\]

    if 4.19865099347443e+74 < b_2

    1. Initial program 41.8

      \[\frac{\left(-b_2\right) - \sqrt{b_2 \cdot b_2 - a \cdot c}}{a}\]
    2. Taylor expanded around inf 5.3

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{c}{b_2} - 2 \cdot \frac{b_2}{a}}\]
  3. Recombined 4 regimes into one program.
  4. Final simplification6.8

    \[\leadsto \begin{array}{l} \mathbf{if}\;b_2 \le -3.727723973148742563324153150500151191249 \cdot 10^{105}:\\ \;\;\;\;\frac{-1}{2} \cdot \frac{c}{b_2}\\ \mathbf{elif}\;b_2 \le 1.364529283357116165462040672443911208369 \cdot 10^{-246}:\\ \;\;\;\;\frac{c}{\sqrt{b_2 \cdot b_2 - a \cdot c} - b_2}\\ \mathbf{elif}\;b_2 \le 4.198650993474429809884798868723112488797 \cdot 10^{74}:\\ \;\;\;\;\frac{-b_2}{a} - \frac{\sqrt{b_2 \cdot b_2 - a \cdot c}}{a}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{2} \cdot \frac{c}{b_2} - 2 \cdot \frac{b_2}{a}\\ \end{array}\]

Reproduce

herbie shell --seed 2019322 
(FPCore (a b_2 c)
  :name "NMSE problem 3.2.1"
  :precision binary64
  (/ (- (- b_2) (sqrt (- (* b_2 b_2) (* a c)))) a))