\[\frac{2}{\left(\left(\frac{{t}^{3}}{\ell \cdot \ell} \cdot \sin k\right) \cdot \tan k\right) \cdot \left(\left(1 + {\left(\frac{k}{t}\right)}^{2}\right) - 1\right)}\]

\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)}

double f(double t, double l, double k) {
        double r62591115 = 2.0;
        double r62591116 = t;
        double r62591117 = 3.0;
        double r62591118 = pow(r62591116, r62591117);
        double r62591119 = l;
        double r62591120 = r62591119 * r62591119;
        double r62591121 = r62591118 / r62591120;
        double r62591122 = k;
        double r62591123 = sin(r62591122);
        double r62591124 = r62591121 * r62591123;
        double r62591125 = tan(r62591122);
        double r62591126 = r62591124 * r62591125;
        double r62591127 = 1.0;
        double r62591128 = r62591122 / r62591116;
        double r62591129 = pow(r62591128, r62591115);
        double r62591130 = r62591127 + r62591129;
        double r62591131 = r62591130 - r62591127;
        double r62591132 = r62591126 * r62591131;
        double r62591133 = r62591115 / r62591132;
        return r62591133;
}

Reproduce

herbie shell --seed 2019172 +o rules:numerics
(FPCore (t l k)
  :name "Toniolo and Linder, Equation (10-)"
  (/ 2.0 (* (* (* (/ (pow t 3.0) (* l l)) (sin k)) (tan k)) (- (+ 1.0 (pow (/ k t) 2.0)) 1.0))))

Timeout in 10.0m

Reproduce