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

\frac{\left(-b_2\right) - \sqrt{b_2 \cdot b_2 - a \cdot c}}{a}

double f(double a, double b_2, double c) {
        double r28774 = b_2;
        double r28775 = -r28774;
        double r28776 = r28774 * r28774;
        double r28777 = a;
        double r28778 = c;
        double r28779 = r28777 * r28778;
        double r28780 = r28776 - r28779;
        double r28781 = sqrt(r28780);
        double r28782 = r28775 - r28781;
        double r28783 = r28782 / r28777;
        return r28783;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2020045 +o rules:numerics
(FPCore (a b_2 c)
  :name "NMSE problem 3.2.1"
  :precision binary64
  (/ (- (- b_2) (sqrt (- (* b_2 b_2) (* a c)))) a))

Backtrace

hash-ref: no value found for key key: '(* #<enode 795(795)> #<enode 0(394)>)		L	C
for-loop	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/egraph.rkt	270	6
update-leader!	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/egraph.rkt	265	0
for-loop	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/main.rkt	77	2
prune-phase	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/main.rkt	74	0
for-loop	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/core/simplify.rkt	80	4
for-loop	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/core/simplify.rkt	76	2
(unnamed)	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/core/simplify.rkt	56	0
(unnamed)	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/core/simplify.rkt	38	0
simplify!	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/mainloop.rkt	224	0
run-iter!	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/mainloop.rkt	327	0
for-loop	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/mainloop.rkt	365	4
run-improve47	/data/pavpan/nightlies/herbie/simplify-upwards-no-duplicates/src/mainloop.rkt	346	0
.../more-scheme.rkt:261:28	unknown
run	/opt/racket-7.5/share/pkgs/profile-lib/main.rkt	39	2
profile-thunk16	/opt/racket-7.5/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/opt/racket-7.5/collects/racket/private/more-scheme.rkt	261	28

Falling back on racket egraph because egg-herbie package not installed (more)

Reproduce

Backtrace