\[\frac{\cos \left(2 \cdot x\right)}{{cos}^{2} \cdot \left(\left(x \cdot {sin}^{2}\right) \cdot x\right)}\]
\frac{\cos \left(2 \cdot x\right)}{{cos}^{2} \cdot \left(\left(x \cdot {sin}^{2}\right) \cdot x\right)}
double f(double x, double cos, double sin) {
        double r12442 = 2.0;
        double r12443 = x;
        double r12444 = r12442 * r12443;
        double r12445 = cos(r12444);
        double r12446 = cos;
        double r12447 = pow(r12446, r12442);
        double r12448 = sin;
        double r12449 = pow(r12448, r12442);
        double r12450 = r12443 * r12449;
        double r12451 = r12450 * r12443;
        double r12452 = r12447 * r12451;
        double r12453 = r12445 / r12452;
        return r12453;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2020045 +o rules:numerics
(FPCore (x cos sin)
  :name "cos(2*x)/(cos^2(x)*sin^2(x))"
  :precision binary64
  (/ (cos (* 2 x)) (* (pow cos 2) (* (* x (pow sin 2)) x))))

Backtrace

hash-ref: no value found for key key: '(pow #<enode 73(73)> #<enode 3(97)>)LC
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/egraph.rkt2706
update-leader!/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/egraph.rkt2650
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/main.rkt772
prune-phase/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/main.rkt740
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt804
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt762
(unnamed)/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt560
(unnamed)/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt380
simplify!/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt2240
run-iter!/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt3270
for-loop/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt3654
run-improve47/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt3460
.../more-scheme.rkt:261:28unknown
run/opt/racket-7.5/share/pkgs/profile-lib/main.rkt392
profile-thunk16/opt/racket-7.5/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-7.5/collects/racket/private/more-scheme.rkt26128