\frac{2}{\left(\left(\frac{{t}^{3}}{\ell \cdot \ell} \cdot \sin k\right) \cdot \tan k\right) \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) + 1\right)}\begin{array}{l}
\mathbf{if}\;t \le -4.86000581215833313418115808157717702245 \cdot 10^{-239} \lor \neg \left(t \le 4.402616231627377082170896165667420584389 \cdot 10^{-246}\right):\\
\;\;\;\;\frac{2}{\left(\frac{\tan k}{\frac{\ell}{{\left(\sqrt[3]{t}\right)}^{3}}} \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) + 1\right)\right) \cdot \left({\left(\sqrt[3]{t}\right)}^{3} \cdot \left(\frac{{\left(\sqrt[3]{t}\right)}^{3}}{\ell} \cdot \sin k\right)\right)}\\
\mathbf{else}:\\
\;\;\;\;\frac{2}{\frac{\left({\left(\sqrt[3]{t}\right)}^{3} \cdot \left(\frac{k \cdot t}{\ell} - \frac{1}{6} \cdot \frac{{k}^{3} \cdot t}{\ell}\right)\right) \cdot \tan k}{\frac{\ell}{{\left(\sqrt[3]{t}\right)}^{3}}} \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) + 1\right)}\\
\end{array}double f(double t, double l, double k) {
double r129970 = 2.0;
double r129971 = t;
double r129972 = 3.0;
double r129973 = pow(r129971, r129972);
double r129974 = l;
double r129975 = r129974 * r129974;
double r129976 = r129973 / r129975;
double r129977 = k;
double r129978 = sin(r129977);
double r129979 = r129976 * r129978;
double r129980 = tan(r129977);
double r129981 = r129979 * r129980;
double r129982 = 1.0;
double r129983 = r129977 / r129971;
double r129984 = pow(r129983, r129970);
double r129985 = r129982 + r129984;
double r129986 = r129985 + r129982;
double r129987 = r129981 * r129986;
double r129988 = r129970 / r129987;
return r129988;
}
double f(double t, double l, double k) {
double r129989 = t;
double r129990 = -4.860005812158333e-239;
bool r129991 = r129989 <= r129990;
double r129992 = 4.402616231627377e-246;
bool r129993 = r129989 <= r129992;
double r129994 = !r129993;
bool r129995 = r129991 || r129994;
double r129996 = 2.0;
double r129997 = k;
double r129998 = tan(r129997);
double r129999 = l;
double r130000 = cbrt(r129989);
double r130001 = 3.0;
double r130002 = pow(r130000, r130001);
double r130003 = r129999 / r130002;
double r130004 = r129998 / r130003;
double r130005 = 1.0;
double r130006 = r129997 / r129989;
double r130007 = pow(r130006, r129996);
double r130008 = r130005 + r130007;
double r130009 = r130008 + r130005;
double r130010 = r130004 * r130009;
double r130011 = r130002 / r129999;
double r130012 = sin(r129997);
double r130013 = r130011 * r130012;
double r130014 = r130002 * r130013;
double r130015 = r130010 * r130014;
double r130016 = r129996 / r130015;
double r130017 = r129997 * r129989;
double r130018 = r130017 / r129999;
double r130019 = 0.16666666666666666;
double r130020 = 3.0;
double r130021 = pow(r129997, r130020);
double r130022 = r130021 * r129989;
double r130023 = r130022 / r129999;
double r130024 = r130019 * r130023;
double r130025 = r130018 - r130024;
double r130026 = r130002 * r130025;
double r130027 = r130026 * r129998;
double r130028 = r130027 / r130003;
double r130029 = r130028 * r130009;
double r130030 = r129996 / r130029;
double r130031 = r129995 ? r130016 : r130030;
return r130031;
}



Bits error versus t



Bits error versus l



Bits error versus k
Results
if t < -4.860005812158333e-239 or 4.402616231627377e-246 < t Initial program 30.6
rmApplied add-cube-cbrt30.8
Applied unpow-prod-down30.8
Applied times-frac23.1
Applied associate-*l*21.2
rmApplied unpow-prod-down21.2
Applied associate-/l*15.5
rmApplied associate-*l/14.5
Applied associate-*l/13.0
rmApplied *-un-lft-identity13.0
Applied times-frac12.1
Applied associate-*l*10.4
if -4.860005812158333e-239 < t < 4.402616231627377e-246Initial program 64.0
rmApplied add-cube-cbrt64.0
Applied unpow-prod-down64.0
Applied times-frac64.0
Applied associate-*l*64.0
rmApplied unpow-prod-down64.0
Applied associate-/l*58.5
rmApplied associate-*l/58.5
Applied associate-*l/58.5
Taylor expanded around 0 43.6
Final simplification12.7
herbie shell --seed 2019325
(FPCore (t l k)
:name "Toniolo and Linder, Equation (10+)"
:precision binary64
(/ 2 (* (* (* (/ (pow t 3) (* l l)) (sin k)) (tan k)) (+ (+ 1 (pow (/ k t) 2)) 1))))