\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 1.1180053642670318 \cdot 10^{-203}:\\
\;\;\;\;\frac{2}{\frac{{k}^{2} \cdot \left(t \cdot {\left(\sin k\right)}^{2}\right)}{\cos k \cdot {\ell}^{2}} + 2 \cdot \frac{{t}^{3} \cdot {\left(\sin k\right)}^{2}}{\cos k \cdot {\ell}^{2}}}\\
\mathbf{else}:\\
\;\;\;\;\frac{2}{\left(\sqrt[3]{\frac{{t}^{\left(\frac{3}{2}\right)}}{\ell} \cdot \left(\left(\frac{{t}^{\left(\frac{3}{2}\right)}}{\ell} \cdot \sin k\right) \cdot \left(\tan k \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) + 1\right)\right)\right)} \cdot \sqrt[3]{\frac{{t}^{\left(\frac{3}{2}\right)}}{\ell} \cdot \left(\left(\frac{{t}^{\left(\frac{3}{2}\right)}}{\ell} \cdot \sin k\right) \cdot \left(\tan k \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) + 1\right)\right)\right)}\right) \cdot \sqrt[3]{\frac{{t}^{\left(\frac{3}{2}\right)}}{\ell} \cdot \left(\left(\frac{{t}^{\left(\frac{3}{2}\right)}}{\ell} \cdot \sin k\right) \cdot \left(\tan k \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) + 1\right)\right)\right)}}\\
\end{array}double f(double t, double l, double k) {
double r275010 = 2.0;
double r275011 = t;
double r275012 = 3.0;
double r275013 = pow(r275011, r275012);
double r275014 = l;
double r275015 = r275014 * r275014;
double r275016 = r275013 / r275015;
double r275017 = k;
double r275018 = sin(r275017);
double r275019 = r275016 * r275018;
double r275020 = tan(r275017);
double r275021 = r275019 * r275020;
double r275022 = 1.0;
double r275023 = r275017 / r275011;
double r275024 = pow(r275023, r275010);
double r275025 = r275022 + r275024;
double r275026 = r275025 + r275022;
double r275027 = r275021 * r275026;
double r275028 = r275010 / r275027;
return r275028;
}
double f(double t, double l, double k) {
double r275029 = t;
double r275030 = 1.1180053642670318e-203;
bool r275031 = r275029 <= r275030;
double r275032 = 2.0;
double r275033 = k;
double r275034 = 2.0;
double r275035 = pow(r275033, r275034);
double r275036 = sin(r275033);
double r275037 = pow(r275036, r275034);
double r275038 = r275029 * r275037;
double r275039 = r275035 * r275038;
double r275040 = cos(r275033);
double r275041 = l;
double r275042 = pow(r275041, r275034);
double r275043 = r275040 * r275042;
double r275044 = r275039 / r275043;
double r275045 = 3.0;
double r275046 = pow(r275029, r275045);
double r275047 = r275046 * r275037;
double r275048 = r275047 / r275043;
double r275049 = r275032 * r275048;
double r275050 = r275044 + r275049;
double r275051 = r275032 / r275050;
double r275052 = 3.0;
double r275053 = r275052 / r275034;
double r275054 = pow(r275029, r275053);
double r275055 = r275054 / r275041;
double r275056 = r275055 * r275036;
double r275057 = tan(r275033);
double r275058 = 1.0;
double r275059 = r275033 / r275029;
double r275060 = pow(r275059, r275032);
double r275061 = r275058 + r275060;
double r275062 = r275061 + r275058;
double r275063 = r275057 * r275062;
double r275064 = r275056 * r275063;
double r275065 = r275055 * r275064;
double r275066 = cbrt(r275065);
double r275067 = r275066 * r275066;
double r275068 = r275067 * r275066;
double r275069 = r275032 / r275068;
double r275070 = r275031 ? r275051 : r275069;
return r275070;
}



Bits error versus t



Bits error versus l



Bits error versus k
Results
if t < 1.1180053642670318e-203Initial program 64.0
Taylor expanded around inf 43.0
if 1.1180053642670318e-203 < t Initial program 28.6
rmApplied sqr-pow28.6
Applied times-frac17.6
Applied associate-*l*14.9
rmApplied associate-*l*14.8
rmApplied associate-*l*13.1
rmApplied add-cube-cbrt13.3
Final simplification16.8
herbie shell --seed 2020046
(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))))