\[\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}\]

\frac{6 \cdot \left(x - 1\right)}{\left(x + 1\right) + 4 \cdot \sqrt{x}}

double f(double x) {
        double r9183 = 6.0;
        double r9184 = x;
        double r9185 = 1.0;
        double r9186 = r9184 - r9185;
        double r9187 = r9183 * r9186;
        double r9188 = r9184 + r9185;
        double r9189 = 4.0;
        double r9190 = sqrt(r9184);
        double r9191 = r9189 * r9190;
        double r9192 = r9188 + r9191;
        double r9193 = r9187 / r9192;
        return r9193;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019305 
(FPCore (x)
  :name "Data.Approximate.Numerics:blog from approximate-0.2.2.1"
  :precision binary64

  :herbie-target
  (/ 6 (/ (+ (+ x 1) (* 4 (sqrt x))) (- x 1)))

  (/ (* 6 (- x 1)) (+ (+ x 1) (* 4 (sqrt x)))))

Backtrace

hash-ref: no value found for key key: 6.0		L	C
for-loop	/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/eggmath.rkt	70	6
egg-parsed->expr	/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/eggmath.rkt	65	0
for-loop	/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/eggmath.rkt	70	6
egg-parsed->expr	/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/eggmath.rkt	65	0
(unnamed)	/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/simplify.rkt	49	8
egraph-add-exprs	/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/eggmath.rkt	122	0
egraph-run	/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/eggmath.rkt	55	0
(unnamed)	/data/pavpan/nightlies/herbie/eggmath-testversion/src/core/simplify.rkt	38	0
simplify!	/data/pavpan/nightlies/herbie/eggmath-testversion/src/mainloop.rkt	223	0
run-improve47	/data/pavpan/nightlies/herbie/eggmath-testversion/src/mainloop.rkt	345	0
(unnamed)	/opt/racket-7.2/collects/racket/private/more-scheme.rkt	261	28
run	/opt/racket-7.2/share/pkgs/profile-lib/main.rkt	39	2
profile-thunk16	/opt/racket-7.2/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/opt/racket-7.2/collects/racket/private/more-scheme.rkt	261	28